Mom -- Typesetting Macros

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# THE TYPESETTING MACROS

Introduction to the typesetting macros

- PAGE SETUP
  - Introduction to Page Setup
  - List of macros
- BASIC TYPESETTING PARAMETERS
  - Introduction to Basic Parameters
  - List of macros
- JUSTIFYING, QUADDING, FILLING, BREAKING LINES
  - Introduction to justify, quad, fill, break
  - List of macros
- TYPOGRAPHIC REFINEMENTS
  - Introduction to typographic refinements
  - List of macros
- TYPE MODIFICATIONS -- pseudo italic, bold, condense, extend
  - Introduction to type modifications
  - List of macros
- VERTICAL MOVEMENTS
  - Introduction to vertical movements
  - List of macros
- TABS
  - Introduction to tabs
  - Typesetting tabs
    - Quickie tutorial
  - String tabs
    - Quickie tutorial
  - List of macros
- MULTI-COLUMNS
  - Introduction to multi-columns
  - List of macros
- INDENTS
  - Introduction to indents
  - List of macros
- GOODIES
  - Introduction to goodies
  - List of macros
- INLINE ESCAPES
  - Introduction to inline escapes
  - List of inline escapes

## Introduction to the typesetting macros

Mom's typesetting macros provide access to groff's typesetting capabilities. Aside from controlling basic type parameters (family, font, line length, point size, leading), mom's macros fine-tune wordspacing, letterspacing, kerning, hyphenation, and so on. In addition, mom has true typesetting tabs, string tabs, multiple indent styles, line padding, and a batch of other goodies.

In some cases, mom's typesetting macros merely imitate groff primitives. In others, they approach typesetting concerns in conceptually new ways (for groff, at least). This should present no problem for newcomers to groff who are learning mom. Old groff hands should be careful. Just because it looks like a duck and walks like a duck does not, in this instance, mean that it is a duck. When using mom, stay away from groff primitives if mom provides a macro that accomplishes the same thing.

Mom's typesetting macros can be used as a standalone package, independent of the document processing macros. With them, you can typeset on-the-fly. Document covers, your best friend's résumé, a poster for a lost dog -- none of these requires structured document processing (page headers, paragraphs, heads, footnotes, etc). What they do demand is precise control over every element on the page. The typesetting macros give you that control.

## Page setup: paper size and page margins

The page setup macros establish the physical dimensions of your page and the margins you want it to have. Groff has defaults for these, but I recommend setting them at the top of your files anyway unless you're using mom's document processing macros and are content with her defaults.

The PAPER macro provides a shortcut for setting the page to the correct dimensions for a number of well-known, established paper sizes. The PAGE macro provides a convenient way of setting the page dimensions and some or all of the page margins with a single macro.

### Page setup macros list

- PAGEWIDTH (page width)
- PAGELENGTH (page length)
- PAPER (common paper sizes)
- L_MARGIN (left margin)
- R_MARGIN (right margin)
- T_MARGIN (top margin)
- B_MARGIN (bottom margin)
- PAGE (page dimensions and margins all in one fell swoop)
- NEWPAGE (start a new page)

### Page width

Macro: PAGEWIDTH <width of printer sheet>
*Requires a unit of measure

The argument to PAGEWIDTH is the width of your printer sheet. PAGEWIDTH requires a unit of measure. Decimal fractions are allowed. Hence, to tell mom the width of your printer sheet is 8-1/2 inches, you enter

    	.PAGEWIDTH 8.5i

### Page length

Macro: PAGELENGTH <length of printer sheet>
*Requires a unit of measure

PAGELENGTH tells mom how long your printer sheet is. It works just like PAGEWIDTH. Therefore, to tell mom your printer sheet is 11 inches long, you enter

    	.PAGELENGTH 11i

### Paper

Macro: PAPER <paper type>

PAPER provides a convenient way to set the page dimensions for some common printer sheet sizes. <paper type> can be one of:

    	LETTER
    	LEGAL
    	STATEMENT
    	TABLOID
    	LEDGER
    	FOLIO
    	QUARTO
    	10x14
    	EXECUTIVE
    	A3
    	A4
    	A5
    	B4
    	B5

Say, for example, you have A4-sized sheets in your printer. It's shorter (and easier) to enter

    	.PAPER A4

than to remember the correct dimensions and enter

    	.PAGEWIDTH  595p
    	.PAGELENGTH 842p

### Left margin

Macro: L_MARGIN <left margin>
*Requires a unit of measure

L_MARGIN establishes the distance from the left edge of the printer sheet at which you want your type to start. It may be used any time, and remains in effect until you enter a new value.

Left indents and tabs are calculated from the value you pass to L_MARGIN, hence it's always a good idea to invoke it before starting any serious typesetting. A unit of measure is required. Decimal fractions are allowed. Therefore, to set the left margin at 3 picas (1/2 inch), you'd enter either

    	.L_MARGIN 3P
    	  or
    	.L_MARGIN .5i

If you use the macros PAGE, PAGEWIDTH or PAPER without invoking L_MARGIN (either before or afterwards), mom automatically sets L_MARGIN to 1 inch.

NOTE: L_MARGIN behaves in a special way when you're using the document processing macros. See Typesetting Macros in Document Processing for an explanation.

### Right margin

Macro: R_MARGIN <right margin>
*Requires a unit of measure

R_MARGIN establishes the amount of space you want between the end of typeset lines and the right hand edge of the printer sheet. In other words, it sets the line length. R_MARGIN requires a unit of measure. Decimal fractions are allowed.

The line length macro (LL) can be used in place of R_MARGIN. In either case, the last one invoked sets the line length. The choice of which to use is up to you. In some instances, you may find it easier to think of a section of type as having a right margin. In others, giving a line length may make more sense.

For example, if you're setting a page of type you know should have 6-pica margins left and right, it makes sense to enter a left and right margin, like this:

    	.L_MARGIN 6P
    	.R_MARGIN 6P

That way, you don't have to worry about calculating the line length. On the other hand, if you know the line length for a patch of type should be 17 picas and 3 points, entering the line length with LL is much easier than calculating the right margin.

    	.LL 17P+3p

If you use the macros PAGE, PAGEWIDTH or PAPER without invoking R_MARGIN afterwards, mom automatically sets R_MARGIN to 1 inch. If you set a line length after these macros (with LL), the line length calculated by R_MARGIN is, of course, overridden.

IMPORTANT: R_MARGIN, if used, MUST come after PAPER, PAGEWIDTH, L_MARGIN and/or PAGE (if a right margin isn't given to PAGE). The reason is that R_MARGIN calculates line length from the overall page dimensions and the left margin. Obviously, it can't make the calculation if it doesn't know the page width and the left margin.

NOTE: R_MARGIN behaves in a special way when you're using the document processing macros. See Typesetting Macros in Document Processing for an explanation.

### Top margin

Macro: T_MARGIN <top margin>
*Requires a unit of measure

T_MARGIN establishes the distance from the top of the printer sheet at which you want your type to start. It requires a unit of measure, and decimal fractions are allowed. To set a top margin of 2-1/2 centimeters, you'd enter

    	.T_MARGIN 2.5c

T_MARGIN calculates the vertical position of the first line of type on a page by treating the top edge of the printer sheet as a baseline. Therefore,

    	.T_MARGIN 1.5i

puts the baseline of the first line of type 1-1/2 inches beneath the top of the page.

IMPORTANT: T_MARGIN does two things: it establishes the top margin for pages that come after it AND it moves to that position on the current page. Therefore, T_MARGIN should only be used at the top of a file (prior to entering text) or after NEWPAGE, like this:

    	.NEWPAGE
    	.T_MARGIN 6P
    	<text>

NOTE: T_MARGIN means something slightly different when you're using the document processing macros. See Top and bottom margins in document processing for an explanation.

### Bottom margin

Macro: B_MARGIN <bottom margin>
*Requires a unit of measure

B_MARGIN sets a nominal position at the bottom of the page beyond which you don't want your type to go. When the bottom margin is reached, mom starts a new page. B_MARGIN requires a unit of measure. Decimal fractions are allowed. To set a nominal bottom margin of 3/4 inch, enter

    	.B_MARGIN .75i

Obviously, if you haven't spaced the type on your pages so that the last lines fall perfectly at the bottom margin, the margin will vary from page to page. Usually, but not always, the last line of type that fits on a page before the bottom margin causes mom to start a new page.

Occasionally, owing to a peculiarity in groff, an extra line will fall below the nominal bottom margin. If you're using the document processing macros, this is unlikely to happen; the document processing macros are very hard-nosed about aligning bottom margins.

NOTE: The meaning of B_MARGIN is slightly different when you're using the document processing macros. See Top and bottom margins in document processing for an explanation.

### Page

Macro: PAGE <width> [ <length> [ <lm> [ <rm> [ <tm> [ <bm> ] ] ] ] ]
*All arguments require a unit of measure

PAGE lets you establish paper dimensions and page margins with a single macro. The only required argument is page width. The rest are optional, but they must appear in order and you can't skip over any. <lm>, <rm>, <tm> and <bm> refer to the left, right, top and bottom margins respectively.

Assuming your page dimensions are 11 inches by 17 inches, and that's all you want to set, enter

    	.PAGE 11i 17i

If you want to set the left margin as well, say, at 1 inch, PAGE would look like this:

    	.PAGE 11i 17i 1i

Now suppose you also want to set the top margin, say, at 1-1/2 inches. <tm> comes after <rm> in the optional arguments, but you can't skip over any arguments, therefore to set the top margin, you must also give a right margin. The PAGE macro would look like this:

            .PAGE 11i 17i 1i 1i 1.5i
                             |   |
            required right___|   |___top margin
                    margin

Clearly, PAGE is best used when you want a convenient way to tell mom just the dimensions of your printer sheet (width and length), or when you want to tell her everything about the page (dimensions and all the margins), for example

    	.PAGE 8.5i 11i 45p 45p 45p 45p

This sets up an 8-1/2 by 11 inch page with margins of 45 points (5/8-inch) all around.

NOTE: Only use PAGE at the start of a document, before entering any text. And remember, when you're using the document processing macros, top margin and bottom margin mean something slightly different than when you're using just the typesetting macros (see Top and bottom margins in document processing).

Additionally, if you invoke PAGE with a top margin argument, any macros you invoke after PAGE will almost certainly move the baseline of the first line of text down by one linespace. To compensate, do

    	.RLD 1v

immediately before entering any text, or, if it's feasible, make PAGE the last macro you invoke prior to entering text.

### Start a new page

Macro: NEWPAGE

Whenever you want to start a new page, use NEWPAGE, by itself with no argument. Mom will finish up processing the current page and move you to the top of a new one (subject to the top margin set with T_MARGIN.

Experts: NEWPAGE is an alias of .bp. You can use either, or mix 'n' match with impunity.

## Basic Typesetting Parameters

Basic parameter macros deal with the fundamental requirements for setting type: family, font, point size, leading and line length.

If you're using the typesetting macros only, the arguments passed to the basic parameter macros remain in effect until you change them. The document processing macros handle things differently. See Typesetting Macros in Document Processing for an explanation.

### Basic parameter macros list

- FAMILY (type family)
- FONT (font)
- PT_SIZE (point size of type)
- LS (line spacing/leading)
- AUTOLEAD (automatic line spacing)
- LL (line length)

### Type family

Macro: FAMILY <family>
Alias: FAM

FAMILY takes one argument: the name of the type family you want. Groff comes with a number of PostScript families, each identified by a 1-, 2- or 3-letter mnemonic. The standard families are:

| A | Avant Garde
| BM | Bookman
| H | Helvetica
| N | New Century Schoolbook
| P | Palatino
| T | Times Roman

The argument you pass to FAMILY is the identifier at left above. For example, if you want Helvetica, enter

    	.FAMILY H

NOTE: The font macro (FT) lets you to specify both the type family and the desired font with a single macro. While this saves a few keystrokes, I recommend using FAMILY for family, and FT for font, except where doing so is genuinely inconvenient.

Experts:
If you add other PostScript families to groff's /font/devps directory, be sure to follow the groff standard for naming families and fonts. For example, if you add the Garamond family, name the font files

    	GARAMONDR
    	GARAMONDI
    	GARAMONDB
    	GARAMONDBI

GARAMOND then becomes a legal family name you can pass to FAMILY. (You could, of course, shorten GARAMOND to just G, or GD.) R, I, B, and BI after GARAMOND are the roman, italic, bold and bold-italic fonts respectively.

### Font

Macro: FT R | I | B | BI

FT takes one of four possible arguments specifying the desired font:

| R | = | roman
| I | = | italic
| B | = | bold
| BI | = | bold-italic

For example, if your family is Helvetica, entering

    	.FT B

will give you the Helvetica bold font. If your family were Palatino, you'd get the Palatino bold font.

You can specify both family and font in the FT macro. As an example,

    	.FT HB

sets the font to Helvetica bold. I strongly recommend keeping family and font separate.

Fonts can also be changed inline. See Inline Escapes, font control.

### Point size of type

Macro: PT_SIZE <size of type in points>
*Does not require a unit of measure

PT_SIZE (Point Size) takes one argument: the size of type in points. Unlike most other macros that establish the size or measure of something, PT_SIZE does not require that you supply a unit of measure since it's a near universal convention that type size is measured in points. Therefore, to change the type size to, say, 11 points, enter

    	.PT_SIZE 11

Point sizes may be fractional (e.g. 10.25 or 12.5).

You can prepend a plus or a minus sign to the argument to PT_SIZE, in which case the point size will be changed by + or - the original value. For example, if the point size is 12, and you want 14, you can do

    	.PT_SIZE +2

then later reset it to 12 with

    	.PT_SIZE -2

The size of type can also be changed inline. See Inline Escapes, changing point size.

### Line spacing/leading

Macro: LS <distance between lines>
*Does not require a unit of measure

LS (Line Space) takes one argument: the distance you want, typically in points, from baseline to baseline of type. The argument may be fractional (e.g. 12.25 or 14.5). Like PT_SIZE, LS does not require a unit of measure, since leading is most often given in points. Therefore, to set the linespace to 14 points, you would enter

    	.LS 14

However, if you wish, you may specify a unit of measure by appending it directly to the argument passed to LS. For example, if you want a linespace of 1/4 of an inch, enter

    	.LS .25i

You can prepend a plus or a minus sign to the argument to LS, in which case the line spacing will be changed by + or - the original value. For example, if the line spacing is 14 points, and you want 17 points, you can do

    	.LS +3

then later reset it to 14 points with

    	.LS -3

Experts:
LS should not be confused with the groff primitive ls. LS acts like vs. mom does not provide a macro analogous to ls.

### Automatic line spacing

Macro: AUTOLEAD <amount of automatic leading> [FACTOR]
*Does not require a unit of measure

Without the FACTOR argument, AUTOLEAD calculates the linespace for you by adding its argument to the current point size of type. All subsequent PT_SIZE requests automatically update the linespacing by the autolead amount.

Used in this way, AUTOLEAD does not require a unit of measure; points is assumed. However, you may use an alternate unit of measure by appending it to the argument. The argument may be a decimal fraction (e.g. .5 or 2.75).

As an example, if your current point size of type is 12, entering

    	.AUTOLEAD 2

changes the linespace to 14 points, regardless any linespacing already in effect. From here on, every change to the size of type (with PT_SIZE, not inline) changes the linespace as well. If you decrease the type size to 9 points, the leading decreases to 11 points. If you increase the type size to 16 points, the leading increases to 18 points.

Automatic updating of the linespacing continues until you enter a "manual" line space value with LS.

If you give AUTOLEAD the optional FACTOR argument, AUTOLEAD calculates the line space as a factor of the numeric argument you gave AUTOLEAD. For example, if your point size is 12,

    	.AUTOLEAD 1.125 FACTOR

sets the leading at 13.5 points. If you change the point size to 14, the leading automatically changes to 15.75 (14 x 1.125).

NOTE: There's no need to prepend a plus sign (+) to AUTOLEAD's argument, although you may do so if you wish.

### Line length

Macro: LL <line length>
*Requires a unit of measure

LL (Line Length) takes one argument: the distance from the left margin of the page to the maximum allowable point on the right at which groff should place type. The line length, in other words, as the macro suggests.

LL requires a unit of measure. Therefore, to set the line length to 39 picas, you would enter

    	.LL 39P

As with other macros that require a unit of measure, the argument to LL may be fractional. For example,

    	.LL 4.5i

sets the line length to 4-1/2 inches.

NOTE: The right margin macro (R_MARGIN) can also be used to set line length.

## Justifying, quadding, filling and breaking lines

The justification and quadding macros deal with how type aligns along the left and right margins. In a nutshell, type either aligns at the left margin, at the right margin, at both margins, or at neither margin (centered).

These macros also determine whether or not input lines are joined and filled during output.

Additionally, macros that deal with how to break output lines are covered in this section, as is the inline escape for joining output lines.

You may encounter some words here that are unfamiliar. Refer to Typesetting terms and Groff terms for an explanation.

### Justification, quad, fill, and break macro list

- Fill modes
  - JUSTIFY (set lines justified)
  - QUAD (set filled lines flush left, right or centered)
- Nofill modes
  - LEFT (set non-filled lines flush left)
  - RIGHT (set non-filled lines flush right)
  - CENTER (set non-filled lines centered)
- Breaking lines
  - BR (manually break an output line)
  - EL (break a line without advancing to the next output line)
  - SPACE (break a line and add space before the next output line)
  - SPREAD (break and force-justify an output line)
- Joining lines
  - \c inline escape

### Justify lines

Macro: JUSTIFY
Fill mode

JUSTIFY doesn't take an argument. Input lines after JUSTIFY are filled and justified upon output.

To break lines and prevent them from being filled and justified, use the BR macro.

### Quad lines left, right, or center

Macro: QUAD L | LEFT | R | RIGHT | C | CENTER | J | JUSTIFY
Alias: FILL
Fill mode

QUAD takes one argument: the direction in which lines should be quadded. Input lines after QUAD are filled upon output.

If L or LEFT, type is set flush along the left margin.

If R or RIGHT, type is set flush along the right margin.

If C or CENTER type is set centered on the current line length.

J and JUSTIFY justify text, and are included as a convenience only. Obviously, if text is justified, it isn't quadded. QUAD J and QUAD JUSTIFY have exactly the same effect as JUSTIFY.

To break lines and prevent them from being filled, use the BR macro.

### Set non-filled lines flush left, right, or centered

Macro: LEFT Macro: RIGHT Macro: CENTER (alias CENTRE)
Nofill mode

LEFT, RIGHT and CENTER let you enter text on a line for line basis without having to use the BR macro after each line. Consider the following:

    	.QUAD LEFT
    	So runs my dream, but what am I?
    	.BR
    	An infant crying in the night
    	.BR
    	An infant crying for the light
    	.BR
    	And with no language but a cry.
    	.BR

Because text after QUAD is filled, you have to use the BR macro to prevent the lines from running together. Not only is this annoying to type, it's awkward to read in a text editor. Much better to do

    	.LEFT
    	So runs my dream, but what am I?
    	An infant crying in the night
    	An infant crying for the light
    	And with no language but a cry.

IMPORTANT: Because LEFT, RIGHT and CENTER are nofill modes, groff does not always respect the current line length. Input lines that run long may exceed it, or get broken in undesirable ways. Therefore, when using these three macros, you should preview your work to ensure that all lines fit as expected.

### Manually break lines

Macro: BR

When using JUSTIFY or QUAD, BR tells mom about partial lines that you want broken (as opposed to filled). Any partial output line that immediately precedes BR will be quadded in the direction of the current quad, or set flush left if text is justified.

Most of the time, you won't need the BR macro. In fill modes, mom tries to be sensible about where breaks are needed. If the nature of a macro is such that under most circumstances you'd expect a break, mom puts it in herself. Equally, in macros where a break isn't normally desirable, no break occurs. This means text files don't get cluttered with annoying BR's.

NOTE: Lines of text in nofill mode never require a BR. Furthermore, in nofill mode, ALL macros cause a break. If a break is not desired, use the \c inline escape.

Experts: BR is an alias for br. You can use either, or mix 'n' match with impunity.

### Manually break a line without advancing on the page

Macro: EL

The mnemonic "EL" is borrowed from old Compugraphic typesetting systems, where it stood for "End Line." Conceptually, EL is equivalent to the notion of a carriage return with no linefeed.

Every once in a while, the need arises for breaking a line without advancing on the page. Imagine, for example, that you're working from marked-up copy. The markup indicates 24 points of space between two given lines, but the prevailing line spacing is 12.5 points. You may find it more convenient to break the first line with EL and instruct mom to advance 24 points to the next line, rather than calculating the lead that needs to be added to 12.5 to get 24. To demonstrate:

    	.LS 12.5
    	A line of text.
    	.EL
    	.ALD 24p
    	The next line of text.

may be more instuitive than

    	.LS 12.5
    	A line of text.
    	.ALD 11.5p
    	The next line of text.

The first example has the further advantage that should you wish to change the prevailing line space but keep the 24 points lead, you don't have to recalculate the extra space.

"ALD" in the above examples stands for "Advance LeaD" (another mnemonic borrowed from Compugraphic), which is covered in the section Vertical movement.

IMPORTANT: EL does not work as advertised on the last output line of pages that contain a footer trap (e.g. one set with B_MARGIN or in documents formatted using the document processing macros). The reason is that the EL macro itself deposits a line break that trips the trap (hey, I like that -- "trips the trap"), and once the trap has been sprung, mom can't recover. She places the line after the EL on the next page.

If you need EL functionality on the last line of a page with a footer trap, turn the trap off with TRAP, as in this example:

    	3.
    	.TRAP OFF
    	.EL
    	.TRAP
    	\*[FP12]Establish, once and for all, if 42 really is the answer.

The above looks something like this upon output:

    	3.  Establish, once and for all, if 42 really is the answer.

with "3." flush at the left margin, and "Establish, once and for all..." on the same line as "3." but starting 12 points in from the left margin.

If you hadn't turned the trap off for `.EL`, "3." would have appeared at the bottom of the page by itself, with "Establish, once and for all..." appearing at the top of the next page.

### Break lines and add space between

Macro: SPACE <space to add between lines>
Alias: SP

SPACE breaks a line, just like BR, then adds space after the line. With no argument, it adds an extra line space. If you pass it a numeric argument without supplying a unit of measure, it advances that number of extra line spaces. For example:

    	.SPACE

breaks the line then adds an extra linespace, whereas

    	.SPACE 2

breaks the line and adds two extra linespaces.

If you supply a unit of measure, SPACE breaks the line then adds the specified amount of extra space to the current linespace, as in

    	.SPACE 6p

which breaks the line then adds six points of space to the current linespace.

SUGGESTION: SPACE and ALD can be used interchangeably (`.SPACE 6p` and `.ALD 6p` are equivalent). However, ALD without an argument does nothing, whereas SPACE without an argument adds an extra line space. I recommend using SPACE when you want an extra line space (or multiple thereof), and ALD whenever you want some other value of space after a line.

Experts: SPACE is an alias of sp. You can use either, or mix 'n' match with impunity.

### Break and force justify (spread) lines

Macro: SPREAD

Sometimes, you need to break a line of justified text and have it come out fully justified, not quadded left the way it would be with the BR macro. An example of where you'd do this would be when you want to prevent a word at the end of a line from being hyphenated (say, a proper name). SPREAD is the macro that lets you break the line and have it came out fully justified.

Experts: SPREAD is an alias for brp. You can use either, or mix 'n' match with impunity.

### Join input lines

Inline: \c

Sometimes, especially when in one of the nofill modes, a macro will cause a break where you don't want one. In order to prevent this from happening (in other words, to join input lines together, forming one output line), use the groff inline escape \c at the end of each input line to be joined to another, like this:

    	.LEFT
    	.FAMILY T
    	.FT R
    	Some lines of text to be \c
    	.FAMILY H
    	.FT B
    	joined \c
    	.FAMILY T
    	.FT R
    	together.

Upon output, the lines will be joined together to read

    	Some lines of text to be joined together.

with the word "joined" in Helvetica bold. Note the space before \c. Without it, the last three words of the output line would read

    	bejoinedtogether

Please also note that had the example been in one of the fill modes, there'd have been no need for the \c.

## Typographic refinements

The macros in this section help you tweak groff's behaviour, ensuring that your documents look typographically professional.

### Typographic refinements macro list

- Word and sentence spacing
  - WS (word spacing)
  - SS (sentence space)
- Letter spacing (track kerning)
  - RW (reduce whitespace)
  - EW (expand whitespace)
  - BR_AT_LINE_KERN
- Hyphenation
  - HY (turn auto hyphenation on/off, or set specific hyphenation parameters)
  - HY_SET (set all hyphenation parameters)
- Automatic kerning and ligatures
  - KERN (turn automatic pairwise kerning on or off)
  - LIGATURES (turn automatic generation of ligatures on or off)

### Word spacing

Macro: WS <+|-wordspace> | DEFAULT

WS (Word Space) increases or decreases the amount of space between words. In nofill modes, or if QUAD is in effect, the space between words is fixed. Therefore, if you change the word spacing with WS, the change applies uniformly to the space between every word on every line. However, when text is justified, the space between words varies from line to line (in order to justify the text). Consequently, the change you make with WS represents the minimum (and ideal) space groff will try to put between words before deciding whether to hyphenate a final word or to stretch the word spacing.

Word space is relative to type size. Knowing how it's calculated is unimportant. What matters is having a sense of how the value passed to WS affects the look of your type. Generally, in/decreasing the word space by a value of 1 or 2 produces a difference that in many cases is scarcely visible; in/decreasing by a value of 5 or so produces a subtle but noticeable difference; and in/decreasing by a value greater than 10 is always apparent. You should preview your work to assess the effect of WS.

WS takes as its argument a whole number preceded by a plus or minus sign. Therefore, to decrease the word space slightly, you might enter

    	.WS -4

To increase it by a noticeable amount, you might enter

    	.WS +12

You can reset the word spacing to its previous value by switching the plus or minus sign, like this:

    	.WS +4
    	A line of text
    	.WS -4

The `.WS -4` undoes the effect of `.WS +4`. You can also reset WS to its groff default by entering

    	.WS DEFAULT

This can be particularly useful if you've been playing around with plus and minus values, and can't remember by how much you have to in/decrease the word space to get it back to normal.

### Sentence space

Macro: SS <+sentence space> | 0 | DEFAULT

SS (Sentence Space) tells groff how to treat double spaces it encounters between sentences in input lines. If you use SS, input sentences with two spaces after them AND input sentences that fall at the end of input lines all receive a normal word space plus an additional amount of space whose size is determined by the + value passed as an argument to SS. Thus,

    	.SS +2

means that input sentences with two spaces after them receive a normal word space PLUS the +2 value passed to SS.

Like WS, increasing the sentence space by a value of 1 or 2 produces a difference that in many cases is scarcely visible; increasing by a value of 5 or so produces a subtle but noticeable difference (i.e. the space between double-spaced input sentences will be slightly but visibly greater than the space between words); and increasing by a value greater than 10 is always apparent. You should preview your work to assess the effect of SS.

There's an additional argument you can pass SS: the number zero (without the + sign). It's the argument you'll use most often. Typeset copy should never have two spaces between sentences, and the "zero" argument tells groff to give the extra spaces no space at all (effectively removing them). Therefore, if you double-space your sentences (as you should when writing in a text editor), get in the habit of putting

    	.SS 0

at the top of your files.

If you do use SS for something other than ensuring that you don't get unwanted sentence spaces in output copy, you can set or reset the sentence space to the groff default (the same width as a word space, i.e. double-spaced input sentences will appear double-spaced on output as well) with

    	.SS DEFAULT

If you're using the document processing macros and your PRINTSTYLE is TYPEWRITE, `.SS DEFAULT` is the default, because you do want double spaces between sentences in copy that imitates the look of a typewritten document.

IMPORTANT: SS with an argument other than "0" should only be used if you're of the old (and wise) school of typists that puts two spaces between sentences. If you ignore this advice and use SS when you habitually put only one space between sentences, you risk producing output where the space between sentences is not equal.

### Automatic hyphenation control

Macro: HY toggle
Macro: HY LINES <max. number of consecutive hyphenated lines>
Macro: HY MARGIN <size of hyphenation margin>
Macro: HY SPACE <extra interword spacing to prevent hyphenation>
Macro: HY DEFAULT
Aliases: HYPHENATE, HYPHENATION

HY, as you can see, can be invoked with a number of arguments. In all cases, the aliases HYPHENATE or HYPHENATION can be used in place of HY. To aid in understanding the various arguments you can pass to HY, I've broken them down into separate sections.

### 1. HY

HY by itself (i.e. with no argument) simply turns automatic hyphenation on. Any argument other than LINES, MARGIN, SPACE or DEFAULT, turns automatic hyphenation off. For example, as explained in How to read macro arguments, you could turn HY off by entering

    	.HY OFF
    	   or
    	.HY X
    	   or
    	.HY END

HY observes the following default hyphenation rules:

1. Last lines (i.e. ones that will spring a trap -- typically the last line on a page) will not be hyphenated.
2. The first and last two characters of a word are never split off.

### 2. HY LINES

HY LINES sets the maximum number of consecutive hyphenated lines that will appear in output copy. 2 is a very good choice, and you'd set it with

    	.HY LINES 2

By default, when you turn automatic hyphenation on, there is no limit to the number of consecutive hyphenated lines.

NOTE: Discretionary hyphens count when groff is figuring out how many lines to hyphenate; explicit hyphens do not.

### 3. HY MARGIN

HY MARGIN sets the amount of room allowed at the end of a line before hyphenation is tripped (e.g. if there's only 6 points left at the end of a line, groff won't try to hyphenate the next word). HY MARGIN only applies if you're using QUAD, and is really only useful if you're using QUAD LEFT.

As an example, if you don't want groff to hyphenate words when there's only 18 points of space left at the end of a left-quadded line, you'd enter

    	.HY MARGIN 18p

NOTE: The numeric argument after HY MARGIN requires a unit of measure.

### 4. HY SPACE

HY SPACE sets an amount of extra interword space that groff will try to put between words on a line in order to PREVENT hyphenation. HY SPACE applies only to justified lines. Generally speaking, you'll want this value to be quite small, since too big a value will result in lines with gaping holes between the words. A reasonable value might be half a point, or one point, which you'd set with

    	.HY SPACE .5p
    	    or
    	.HY SPACE 1p

NOTE: The numeric argument after HY SPACE requires a unit of measure.

### 4. HY DEFAULT

HY DEFAULT resets automatic hyphenation to its default behaviour, cancelling any changes made with LINES, MARGIN, and/or SPACE.

### A note on hyphenation in general

Hyphenation is a necessary evil. If it can be avoided, it should be. If it can't be, it should occur infrequently. That's the reason for number of parameters you can set with HY.

Furthermore, hyphenation in rag copy requires a great deal of attention. At best, it should be avoided completely by individually adjusting the number of words on consecutive lines to achieve a pleasing, natural-looking rag. Since such adjustments are often too fussy for document processing, I recommend playing around with HY MARGIN a bit if your copy looks hyphen-heavy.

### Set hyphenation parameters all at once

Macro: HY_SET <lines> [ <margin> [ <space> ] ]
Alias: HYSET

HY_SET lets you set the parameters for hyphenation with a single macro. <lines>, <margin> and <space> correspond to the numeric values required by LINES, MARGIN and SPACE as described above.

To set just the maximum number of consecutive hyphenated lines, you'd enter

    	.HY_SET 2

If you wanted the same number of maximum consecutive hyphenated lines and a hyphenation margin for use with rag copy,

    	.HY_SET 2 36p

would set the hyphenation margin to 36 points.

If you wanted the same number of maximum consecutive hyphenated lines and a hyphenation space of 2 points for use with justified copy,

    	.HYSET 2 0 2p

is how you'd do it.

### Reduce whitespace

Macro: RW <amount of whitespace reduction between letters>

RW (Reduce Whitespace) and its corresponding macro, EW (Expand Whitespace), allow you to tighten (or loosen) output lines by uniformly reducing or expanding the space between characters. This is particularly useful when you want to squeeze or stretch lines on a narrow measure.

The value passed to RW may be a whole number or a decimal fraction. Since a value of 1 produces a noticeable reduction in the space between letters at text sizes, you'll most likely use small decimal values when tightening lines. For example,

    	.RW .1
    	  or
    	.RW .2

may be just enough to squeeze an extra character or two on a line without the change in letter spacing being obvious. I highly recommend previewing your work to assess the effect of RW.

IMPORTANT: RW affects all fonts in the family current at the time it's invoked. It must be reset to zero to cancel its effect (`.RW 0`) on those fonts, or reinvoked (possibly with a different value) if you change family.

NOTE: By default, RW does not deposit a break (BR) when it's invoked. If you want RW to break at the ends of the previous input lines, you can tell mom that's what you want by invoking the BR_AT_LINE_KERN toggle macro.

### Expand whitespace

Macro: EW <amount of whitespace expansion between letters>

EW (Expand Whitespace) expands the amount of whitespace between letters, effectively "loosening" lines of type.

The value passed to EW may be a whole number or a decimal fraction. Since a value of 1 produces a noticeable expansion in the space between letters at text sizes, you'll most likely use small decimal values when loosening lines. For example,

    	.EW .1
    	  or
    	.EW .2

may be just enough to open up a line without the change in letter spacing being obvious. I highly recommend previewing your work to assess the effect of EW.

NOTE: By default, EW does not deposit a break (BR) when it's invoked. If you want EW to break at the ends of the previous input lines, you can tell mom that's what you want by invoking the BR_AT_LINE_KERN toggle macro.

### Break before line kerning

Macro: BR_AT_LINE_KERN toggle

By default, mom does not break input lines when you invoke RW or EW. If you'd like mom to break input lines prior to RW or EW, invoke BR_AT_INPUT_LINE without any argument. To disable the breaks, invoke BR_AT_INPUT_LINE with any argument (OFF, QUIT, Q, X...), like this

    	.BR_AT_LINE_KERN OFF
    	    or
    	.BR_AT_LINE_KERN X

### Automatic kerning

Macro: KERN toggle

By itself (i.e. with no argument), KERN turns automatic pairwise kerning on. With any argument (e.g. OFF, Q, X), pairwise kerning is turned off.

Kerning of individual character pairs can be controlled with the inline escapes \*[BU #] and \*[FU #]. See Inline Escapes, kerning.

### Automatic ligature generation

Macro: LIGATURES toggle
Alias: LIG

Provided your current font has ligatures, LIGATURES, by itself, turns on automatic generation of ligatures. When automatic ligature generation is on, simply typing the letters of a ligature combination will produce the correct ligature upon output. For example, if you type the word "finally", the fi combination will be output as an fi ligature. Generally speaking, ligatures are A Good Thing, hence mom has them on by default.

LIGATURES with any argument turns automatic ligature generation off.

NOTE: Not all fonts support ligatures.

## Type modifications: pseudo-italic, -bold, -condensed, -extended

It sometimes happens that a PostScript family doesn't contain all the fonts you need. You might, for example, be missing an italic font, or a bold font. Or you might not be able to get your hands on a condensed family. That's where these macros and inline escapes come in. With them, you can fake the fonts you're missing. A word of caution, though: "faked" fonts are just that -- faked. You should only use them as a last resort, and then only sparingly. A word or two or a line or two in a faked font will pass unnoticed; large patches of type in a faked font look typographically cheap.

### Type modifications macro list

- Pseudo italic
  - SETSLANT -- degree of pseudo-italicising
  - \*[SLANT] -- inline escape for pseudo-italicising type
- Pseudo bold
  - SETBOLDER -- amount of emboldening
  - \*[BOLDER] -- inline escape for emboldening type
- Pseudo condensed
  - CONDENSE -- percentage for pseudo-condensed type
  - \*[COND] -- inline escape for pseudo-condensed type
- Pseudo extended
  - EXTEND -- percentage for pseudo-extended type
  - \*[EXT] -- inline escape for pseudo-extending

### Set degree of slant for pseudo-italicising

Macro: SETSLANT <degrees to slant type> | RESET

Pseudo-italicising of type is accomplished by slanting a roman font a certain number of degrees to the right. SETSLANT lets you fix the number of degrees. Mom's default is 15, which produces an acceptable approximation of an italic font. If you want another value -- say, 13 degrees -- you'd set it by entering

    	.SETSLANT 13

If you change the degree of slant and later want to set it back to the mom default, do

    	.SETSLANT RESET

NOTE: By itself, SETSLANT will not start pseudo-italicising type; it merely tells mom what degree of slant you want. To start pseudo-italicising, use the inline escape \*[SLANT].

### Pseudo italic on/off

Inline: \*[SLANT] -- turn pseudo-italic on
Inline: \*[SLANTX] -- turn pseudo-italic off

\*[SLANT] begins pseudo-italicising type. \*[SLANTX] turns the feature off. Both are inline escapes, therefore they should not appear as separate lines, but rather be embedded in text lines, like this:

    	Not \*[SLANT]everything\*[SLANTX] is as it seems.

Alternatively, if you wanted the whole line pseudo-italicised, you'd do

    	\*[SLANT]Not everything is as it seems.\*[SLANTX]

Once \*[SLANT] is invoked, it remains in effect until turned off.

NOTE: If you're using the document processing macros with PRINTSTYLE TYPEWRITE, mom underlines pseudo-italics by default. To change this behaviour, use the special macro SLANT_MEANS_SLANT.

### Set amount of emboldening

Macro: SETBOLDER <amount of emboldening, in machine units> | RESET

Emboldening of type is accomplished by printing characters twice; the second printing is slightly offset from the first, effectively "thickening" the character. SETBOLDER lets you set the number of machine units for the offset. Mom's default is 700 units, which produces an acceptable approximation of a bold font. If you want another value -- say, 500 units -- you'd set it by entering

    	.SETBOLDER 500

If you change the emboldening offset and later want to set it back to the mom default, do

    	.SETBOLDER RESET

NOTE: By itself, SETBOLDER will not start emboldening type; it merely tells mom what you want the emboldening offset to be. To start emboldening, use the inline escape \*[BOLDER].

### Emboldening on/off

Inline: \*[BOLDER] -- turn emboldening on
Inline: \*[BOLDERX] -- turn emboldening off

\*[BOLDER] begins emboldening type. \*[BOLDERX] turns the feature off. Both are inline escapes, therefore they should not appear as separate lines, but rather be embedded in text lines, like this:

    	Not \*[BOLDER]everything\*[BOLDERX] is as it seems.

Alternatively, if you wanted the whole line emboldened, you'd do

    	\*[BOLDER]Not everything is as it seems.\*[BOLDERX]

Once \*[BOLDER] is invoked, it remains in effect until turned off.

NOTE: If you're using the document processing macros with PRINTSTYLE TYPEWRITE, mom ignores \*[BOLDER] requests.

### Set percentage for pseudo-condensed type

Macro: CONDENSE <pseudo-condense percentage>

Pseudo-condensing of type is accomplished by reducing the width of characters at a given point size without reducing their height, effectively narrowing them so they look like condensed type. CONDENSE tells mom what percentage of the normal character width you want the characters to be condensed.

Mom has no default value for CONDENSE, therefore you must set it before using the inline escape \*[COND]. 80 percent of the normal character width is a good value, and you'd set it like this:

    	.CONDENSE 80

NOTE: By itself, CONDENSE will not start pseudo-condensing type; it merely tells mom what percentage of the normal character width you want characters to be condensed. To start pseudo-condensing, use the inline escape \*[COND].

Additional note: Make sure that pseudo-condensing is off (with \*[CONDX]) before before making any changes to the pseudo-condense percentage with CONDENSE.

### Pseudo-condensing on/off

Inline: \*[COND] -- turn pseudo-condensing on
Inline: \*[CONDX] -- turn pseudo-condensing off

\*[COND] begins pseudo-condensing type. \*[CONDX] turns the feature off. Both are inline escapes, therefore they should not appear as separate lines, but rather be embedded in text lines, like this:

    	\*[COND]Not everything is as it seems.\*[CONDX]

\*[COND] remains in effect until you turn it off with \*[CONDX].

IMPORTANT: You MUST turn \*[COND] off before making any changes to the point size of your type, either via the PT_SIZE macro or with the \s inline escape. If you wish the new point size to be pseudo-condensed, simply reinvoke \*[COND] afterwards. Equally, \*[COND] must be turned off before changing the condense percentage with CONDENSE.

NOTE: If you're using the document processing macros with PRINTSTYLE TYPEWRITE, mom ignores \*[COND] requests.

### Set percentage for pseudo-extended type

Macro: EXTEND <pseudo-extend percentage>

Pseudo-extending of type is accomplished by increasing the width of characters at a given point size without increasing their height, effectively widening them so they look like extended type. EXTEND tells mom what percentage of the normal character width you want the characters to be extended.

Mom has no default value for EXTEND, therefore you must set it before using the inline escape \*[EXT]. 120 percent of the normal character width is a good value, and you'd set it like this:

    	.EXTEND 120

NOTE: By itself, EXTEND will not start pseudo-extending type; it merely tells mom what percentage of the normal character width you want characters to be extended. To start pseudo-extending, use the inline escape \*[EXT].

Additional note: Make sure that pseudo-extending is off (with \*[EXTX]) before before making any changes to the pseudo-extend percentage with EXTEND.

### Pseudo-extending on/off

Inline: \*[EXT] -- turn pseudo-extending on
Inline: \*[EXTX] -- turn pseudo-extending off

\*[EXT] begins pseudo-extending type. \*[EXTX] turns the feature off. Both are inline escapes, therefore they should not appear as separate lines, but rather be embedded in text lines, like this:

    	\*[EXT]Not everything is as it seems.\*[EXTX]

\*[EXT] remains in effect until you turn it off with \*[EXTX].

IMPORTANT: You MUST turn \*[EXT] off before making any changes to the point size of your type, either via the PT_SIZE macro or with the \s inline escape. If you wish the new point size to be pseudo-extended, simply reinvoke \*[EXT] afterwards. Equally, \*[EXT] must be turned off before changing the extend percentage with EXTEND.

NOTE: If you're using the document processing macros with PRINTSTYLE TYPEWRITE, mom ignores \*[EXT] requests.

## Vertical movement

The two macros in this section allow you to move down or up on the page relative to the current baseline.

### Vertical movement macro list

- ALD -- Advance Lead
- RLD -- Reverse Lead

### Advance Lead (move downward)

Macro: ALD <distance to move downward>
*Requires a unit of measure

ALD takes one argument: the distance to move downward on the page relative to the current vertical position.

Used by itself, or preceded by BR, ALD will advance by one line space plus the distance you specify. Preceded by EL, it will advance by exactly the distance you specify.

ALD requires a unit of measure. Decimal fractions are allowed, and values may be combined. Therefore, to move down on the page by 1/4 of an inch, you could enter either

    	.ALD .25i
    	    or
    	.ALD 1P+6p

As the mnemonic (Advance LeaD) suggests, you'll most often use ALD with points of lead.

NOTE: if you want to use ALD at the top of a page (i.e. to advance to the starting position of type on a page), combine the value you want with -1v (minus one line space), like this:

    	.ALD 1i-1v

At the top of a page, this will advance one inch from the top edge of the paper. Without the -1v, the same command would advance one inch from the top of the page plus the distance of one line space.

Important: Do NOT use ALD in this way if you have set a top margin with T_MARGIN or PAGE.

### Reverse Lead (move upward)

Macro: RLD <distance to move upward>
*Requires a unit of measure

RLD takes one argument: the distance to move upward on the page relative to the current vertical position.

Used by itself, or preceded by BR, RLD will advance by one line space, then reverse by the distance you specify. Preceded by EL, it will reverse by exactly the distance you specify.

RLD requires a unit of measure. Decimal fractions are allowed, and values may be combined. Therefore, to move up on the page by 1/4 of an inch, you could enter either

    	.RLD .25i
    	    or
    	.RLD 1P+6p

As the mnemonic (Rdvance LeaD) suggests, you'll most often use RLD with points of lead.

## Tabs

Mom provides two different kinds of tab setup: typesetting tabs and string tabs. Neither one has anything to do with the tab key on your keyboard, and both are utterly divorced from groff's notion of tabs. I recommend reading this section carefully in order to understand how mom handles tabs.

### Typesetting tabs

Typesetting tabs are defined by both an indent from the left margin and a line length. This is quite different from typewriter-style tab stops (the groff norm) that only define the left indent. In conjunction with the multi-column macros, typesetting tabs significantly facilitate tabular and columnar work.

Typesetting tabs are created with the TAB_SET macro. TAB_SET identifies the tab (by number), establishes its left indent and line length, and optionally sets a quad direction and fill mode. After tabs have been created with TAB_SET, they can be called at any time with the TAB macro.

NOTE: see the section Typesetting Macros in Document Processing for information and advice on using tabs with the document processing macros.

### Quickie tutorial on typesetting tabs

Say you want to set up three tabs to produce an employee evaluation that looks something like this:

    	CRITERION       EVALUATION     COMMENTS

    	Service           Good         Many clients specifically request
    	                               support from Joe by name.

    	Punctuality    Satisfactory    Tends to arrive after 8:00am, but
    	                               often works through lunch hour.

    	Team spirit     Needs work     Persistently gives higher priority
    	                               to helping clients than respecting
    	                               organizational hierarchy.

You want the first tab ("CRITERION")

- to begin at the left margin of the page (i.e. no indent)
- to have a line length of 5 picas
- to be set flush left

Tabs must be numbered, and each has to be set up with a separate TAB_SET line. Therefore, to set up tab 1, you enter

       .TAB_SET  1  0  5P  L
                 |  |  |   |
          tab #__|  |  |   |__direction
                    |  |
            indent__|  |__length

You want the second tab ("EVALUATION")

- to begin 8 picas from the left margin
- to have a length of 9 picas
- to be set centered.

You set it up like this:

       .TAB_SET  2  8P  9P  C
                 |  |   |   |
          tab #__|  |   |   |__direction
                    |   |
            indent__|   |__length

You want the third tab ("COMMENTS")

- to begin 19 picas from the left margin
- to have a length of 17 picas
- to be set flush left, filled

The setup looks like this:

       .TAB_SET  3  19P  17P  L  QUAD
                 |   |    |   |    |
                 |   |    |   |    |__fill output lines
                 |   |    |   |
          tab #__|   |    |   |__direction
                     |    |
             indent__|    |__length

Once the tabs are set up, you can call them in one of two ways:

- TAB (with the tab number as an argument) breaks the current line, advances one linespace, and calls the tab.
- TN (Tab Next) keeps you on the current line and moves over to the next tab in sequence (i.e. from 1 to 2, 2 to 3, etc.).

To exit from tabs and restore your original left margin, line length, quad direction and fill mode, use TQ (Tab Quit).

Here's how the input for our sample employee evaluation looks (with some introductory parameters):

    	.PAGE 8.5i 11i 1i 1i 1i
    	.FAMILY  T
    	.FT      R
    	.PT_SIZE 14
    	.LS      16
    	.QUAD    LEFT
    	.KERN
    	.HY OFF
    	.SS 0
    	.TAB_SET 1 0   5P  L
    	.TAB_SET 2 8P  9P  C
    	.TAB_SET 3 19P 17P L QUAD
    	.TAB 1
    	CRITERION
    	.TN
    	EVALUATION
    	.TN
    	COMMENTS
    	.SP
    	.TAB 1
    	Service
    	.TN
    	Good
    	.TN
    	Many clients specifically request support from Joe by name.
    	.SP
    	.TAB 1
    	Punctuality
    	.TN
    	Satisfactory
    	.TN
    	Tends to arrive after 8:00am, but often works through lunch hour.
    	.SP
    	.TAB 1
    	Team spirit
    	.TN
    	Needs work
    	.TN
    	Persistently gives higher priority to helping clients
    	than respecting organizational hierarchy.
    	.TQ

Try setting this up and previewing it with

    	groff -mom -X <filename>

Notice how `.TN` simply moves over to the next tab, while the combination `.SP/.TAB 1` breaks the line, advances by one extra linespace, and calls the first tab.

Notice, too, how the `QUAD` argument passed to tab 3 means you don't have to worry about the length of input lines; mom fills the tab and sets the type flush left.

### String tabs (autotabs)

String tabs let you mark off tab positions inline. Left indents and line lengths are calculated from the beginning and end positions of the marks. This is especially useful when tab indents and lengths need to be determined from the text that goes in each tab.

Setting up string tabs is a two-step procedure. First, you enter an input line in which you mark off where you want tabs to begin and end. (This is often best done in conjunction with the SILENT macro.)

Next, you invoke the ST macro for every string tab you defined, and optionally pass quad and fill information to it. That done, string tabs are called with the TAB macro, just like typesetting tabs.

In combination with the PAD macro and the groff inline escape \h (move horizontally across the page) or mom's \*[FP#] (Forward Points) inline, string tabs provide tremendous flexibility in setting up complex tab structures.

### Quickie tutorial on string tabs

Say you want to set up tabs for the employee evaluation form used as an example in the typesetting tabs tutorial. This time, though, you want to play around with the point size of type, so you can't know exactly how long the tabs will be or where they should start. All you know is

- CRITERION is the longest line in tab 1
- EVALUATION is the longest line in tab 2
- tab 3 should extend to the current right margin
- you want a 1 pica gutter between each tab

This is an ideal job for string tabs.

The first thing you need for string tabs is an input line with tab positions marked on it. Tabs are marked with the inline escapes \*[ST#] and \*[ST#X]. (In this example, we enclose the input line with the SILENT macro so the line doesn't print. We also use the PAD macro to permit defining tab 3 as simply "the amount of space remaining on the input line.")

The setup looks like this:

    	.SILENT
    	.PAD "\*[ST1]CRITERION\*[ST1X]\*[FP12]\*[ST2]EVALUATION\*[ST2X]\*[FP12]\*[ST3]#\*[ST3X]"
    	.SILENT OFF

The long line after `.PAD` looks scary, but it isn't. Here's what it means when broken down into its component parts:

- The longest line in tab 1 is "CRITERION", so we enclose CRITERION with begin/end markers for string tab 1:

  `\*[ST1]CRITERION\*[ST1X]`

- We want a 1 pica (12 points) gutter between tab 1 and 2, so we insert 12 points of space with \*[FP12] (Forward Points 12):

  `\*[FP12]`

- The longest line in tab 2 is "EVALUATION", so we enclose EVALUATION with begin/end markers for string tab 2:

  `\*[ST2]EVALUATION\*[ST2X]`

- We want 1 pica (12 points) between tab 2 and 3, so we insert 12 points of space with another \*[FP12]:

  `\*[FP12]`

- We want tab 3 to be as long as whatever space remains on the current line length, so we enclose the pad marker (#) with begin/end markers for string tab 3:

  `\*[ST3]#\*[ST3X]`

The tabs are now defined, but they require quad direction and fill information. For each string tab defined above, enter a separate ST line, like this:

    	.ST  1  L
    	.ST  2  L
    	.ST  3  L  QUAD
    	     |  |   |
    	     |  |   |__fill output lines
    	     |  |
    	tab__|  |__direction
    	number

From here on in, you call the tabs with TAB and TN just like typesetting tabs (see typesetting tabs tutorial).

Here's the complete setup and entry for the sample employee evaluation form utilising string tabs.

    	.PAGE 8.5i 11i 1i 1i 1i
    	.FAMILY  T
    	.FT      R
    	.PT_SIZE 14
    	.LS      16
    	.QUAD    LEFT
    	.KERN
    	.HY OFF
    	.SS 0
    	.SILENT
    	.PAD "\*[ST1]CRITERION\*[ST1X]\*[FP12]\*[ST2]EVALUATION\*[ST2X]\*[FP12]\*[ST3]#\*[ST3X]"
    	.SILENT OFF
    	.ST  1  L
    	.ST  2  L
    	.ST  3  L  QUAD
    	.TAB 1
    	CRITERION
    	.TN
    	EVALUATION
    	.TN
    	COMMENTS
    	.SP
    	.TAB 1
    	Service
    	.TN
    	Good
    	.TN
    	Many clients specifically request support from Joe by name.
    	.SP
    	.TAB 1
    	Punctuality
    	.TN
    	Satisfactory
    	.TN
    	Tends to arrive after 8:00am, but often works through lunch hour.
    	.SP
    	.TAB 1
    	Team spirit
    	.TN
    	Needs work
    	.TN
    	Persistently gives higher priority to helping clients
    	than respecting organizational hierarchy.
    	.TQ

Try setting this up and previewing it with

    	groff -mom -X <filename>

Now, change the point size of the above sample to 12 and preview it again. You'll see that the tab structure remains identical (tab 1=CRITERION, tab 2=EVALUATION, tab 3=space remaining, and the gutter between tabs is still 1 pica), while the position and length of the tabs have altered because of the new point size.

Now try increasing the gutters to 2 picas (put an additional `\*[FP12]` after each `\*[FP12]`). Preview the file again, and notice how the tab structure remains the same, but the gutters are wider.

### Tabs macro list

- TAB_SET (create typesetting tabs)
- \*[ST]...\*[STX] (inline escapes for marking String Tabs)
- ST (set String Tabs)
- TAB (call tabs)
- TN (Tab Next; call next tab in a sequence)
- TQ (Tab Quit)

### Set up typsetting tabs

Macro: TAB_SET <tab number> <indent> <length> L | R | C | J [ QUAD ]
*<indent> and <length> require a unit of measure

TAB_SET creates typesetting tabs that later can be called with TAB. Typesetting tabs are numbered, and defined by an indent, a length, and a "direction", hence TAB_SET has four required arguments:

- a tab number
- an indent (measured from the left margin of the page, or, if you're already in a tab, from the left margin of the tab)
- a length
- a direction

To set up a centered tab 6 picas long and 9 points from the left margin, you'd enter

    	.TAB_SET 1 9p 6P C

The tab number in the above ("1") is simply an identifier. It could have been 4, or 17, or 296. There's no need to set up tabs in numerical sequence.

By default, tabs are in nofill mode, meaning you can enter text in tabs on a line for line basis without having to use the BR macro. If you want a tab to be filled, pass the optional argument QUAD, which will make the tab behave as if you'd entered `.QUAD L | R | C`.

For justified tabs, simply pass the argument J (without the QUAD argument), like this:

    	.TAB 1 9p 6P J

Once tabs are set, they can be called at any time with the TAB # macro, where "#" is the number of the desired tab.

You can set up any number of typesetting tabs. However, be aware that string tabs are also called with TAB #, so be careful that you don't set up a typesetting tab numbered, say, 4, when you already have a string tab numbered 4. Every tab, typesetting or string, must have a unique numeric identifier.

NOTE: If you use TAB_SET while you're currently inside a tab, the indent argument is the distance from the tab's left margin, not the left margin of the page. Therefore, you should exit tabs (with TQ) before creating new tabs (unless, of course, you want to set up a tab structure within the confines of an existing tab).

IMPORTANT: Turn all indents off (see Indents) before setting up tabs with TAB_SET, or mom may get confused.

### Mark positions of string tabs

Inlines: \*[ST<number>]...\*[ST<number>X]

String tabs need to be marked off with inline escapes before being set up with the ST macro. Any input line may contain string tab markers. <number>, above, means the numeric identifier of the tab. The following shows a sample input line with string tab markers.

    	\*[ST1]Now is the time\*[ST1X] for all \*[ST2]good men\*ST2X] to come to the aid of the party.

String tab 1 begins at the start of the line and ends after the word "time". String tab 2 starts at "good" and ends after "men". Inline escapes (e.g. font or point size changes, or horizontal movements, including padding) are taken into account when mom determines the position and length of string tabs.

Up to nineteen string tabs may be marked (not necessarily all on the same line, of course), and they must be numbered between 1 and 19.

Once string tabs have been marked in input lines, they have to be "set" with ST, after which they may be called, by number, with TAB.

NOTE: Lines with string tabs marked off in them are normal input lines, i.e. they get printed, just like any input line. If you want to set up string tabs without the line printing, use the SILENT macro.

IMPORTANT: Do not try to set up string tabs on a line that is broken with SPREAD. Mom calculates string tab positions and lengths as she reads the input line, not after the line has undergone manipulations to the word spacing.

### Set string tabs

Macro: ST <tab number> L | R | C | J [ QUAD ]

After string tabs have been marked off on an input line (see \*[ST]...\*[STX]), you need to "set" them by giving them a direction and, optionally, the QUAD argument. In this respect, ST is like TAB_SET except that you don't have to give ST an indent or a line length (that's already taken care of, inline, by `\*[ST]...\*[STX]`). If you want string tab 1 to be left, enter

    	.ST 1 L

If you want it to be left and filled, enter

    	.ST 1 L QUAD

If you want it to be justified, enter

    	.ST 1 J

See the Quickie tutorial on string tabs for a full explanation of setting up string tabs.

### Call tabs

Macro: TAB <tab number>
Alias: TB

After tabs have been defined (either with TAB_SET or ST), TAB moves to whatever tab number you pass it as an argument. For example,

    	.TAB 3

moves you to tab 3.

NOTE: TAB breaks the line preceding it and advances 1 linespace. Hence,

    	.TAB 1
    	A line of text in tab 1.
    	.TAB 2
    	A line of text in tab 2.

produces, on output

    	A line of text in tab 1.
    	                           A line of text in tab 2.

If you want the tabs to line up, use TN (Tab Next), like this:

    	.TAB 1
    	A line of text in tab 1.
    	.TN
    	A line of text in tab 2.

which produces

    	A line of text in tab 1.   A line of text in tab 2.

If the text in your tabs runs to several lines, and you want the first lines of each tab to align, you must use the multi-column macros.

ADDITIONAL NOTE: Any indents in effect prior to calling a tab are automatically turned off by TAB. If you were happily zipping down the page with a left indent of 2 picas turned on, and you call a tab whose indent from the left margin is 6 picas, your new distance from the left margin will be 6 picas, not 6 picas plus the 2 pica indent.

### Tab Next

Macro: TN

TN moves over to the next tab in numeric sequence (tab n+1) without advancing on the page. See the NOTE in the description of the TAB macro for an example of how TN works.

NOTE: TN is like EL in that it doesn't work as advertised on the last line before a footer trap is sprung. If you need to use TN on the last line of a page with a footer trap, turn the trap off with TRAP, as in this example:

    	.TAB_SET 1 0  1P  L
    	.TAB_SET 2 1P 20P L
    	.TAB 1
    	.TRAP OFF
    	1.
    	.TN
    	The first rule of survival is "make and keep good friends."
    	.TRAP

The above, at the bottom of a page, will look something like this:

    	1.  The first rule of survival is "make and keep good friends."

If you hadn't turned the trap off before `.TN`, "1." would have appeared as the last line on the page, with "The first rule of survival..." being the first line on the next page.

### Tab Quit

Macro: TQ

TQ takes you out of whatever tab you were in, advances 1 linespace, and restores the left margin, line length, quad direction and fill mode that were in effect prior to invoking any tabs.

## Multi-Columns

Tabs are not by nature columnar, which is to say that if the text inside a tab runs to several lines, calling another tab does not automatically move to the baseline of the first line in the previous tab. To demonstrate:

    	.TAB 1
    	Carrots
    	Potatoes
    	Broccoli
    	.TAB 2
    	$1.99/5 lbs
    	$0.25/lb
    	$0.99/bunch

produces, on output

    	Carrots
    	Potatoes
    	Broccoli
    	           $1.99/5 lbs
    	           $0.25/lb
    	           $0.99/bunch

The multi-column macros allow you to set tabs in columnar fashion, rather than line by line. When you invoke multi-column mode (with MCO), mom saves the position of the current baseline. MCR (Multi-column return) at any point while multi-columns are on returns you to the saved position. Exiting multi-columns (MCX) quits the current tab (if you're in one) and moves you to the bottom of the longest column. (Note that you do not have to use multi-columns in conjunction with tabs.)

Using our example above, but setting it in multi-column mode,

    	.MCO
    	.TAB 1
    	Carrots
    	Potatoes
    	Broccoli
    	.MCR
    	.TAB 2
    	$1.99/5 lbs
    	$0.25/lb
    	$0.99/bunch
    	.MCX

produces

    	Carrots   $1.99/5 lbs
    	Potatoes  $0.25/lb
    	Broccoli  $0.99/bunch

NOTE: Do not confuse MCO with the COLUMNS macro in the document processing macros.

### Columns macro list

- MCO (begin multi-column setting)
- MCR (return to top of column)
- MCX (exit multi-columns)

### Begin multi-column setting

Macro: MCO

MCO (Multi-Column On) is the macro you use to begin multi-column setting. It marks the current baseline as the top of your columns, for use late with MCR. See the introduction to columns for an explanation of multi-columns and some sample input.

NOTE: Do not confuse MCO with the COLUMNS macro in the document processing macros.

### Return to top of column

Macro: MCR

Once you've turned multi-columns on (with MCO), MCR, at any time, returns you to the top of your columns.

### Exit multi-columns

Macro: MCX [ <distance to advance below longest column> ]
*Optional argument requires a unit of measure

MCX takes you out of any tab you were in (by silently invoking TQ) and advances to the bottom of the longest column.

Without an argument, MCX advances 1 linespace below the longest column. Linespace, in this instance, is the leading in effect at the moment MCX is invoked.

If you pass the <distance> argument to MCX, it advances 1 linespace below the longest column (see above) PLUS the distance specified by the argumemnt. The argument requires a unit of measure; therefore, to advance an extra 6 points below where MCX would normally place you, you'd enter

    	.MCX 6p

NOTE: If you wish to advance a precise distance below the baseline of the longest column, use MCX with an argument of 0 (zero; no unit of measure required) in conjunction with the ALD macro, like this:

    	.MCX 0
    	.ALD 24p

The above advances to precisely 24 points below the baseline of the longest column.

## Indents

With mom's indents, you can indent from the left, the right, or both margins. In addition, mom provides temporary left indents (i.e. only one line is indented, as at the start of a paragraph) and "hanging" left indents (the reverse of a temporary indent; the first line isn't indented, subsequent lines are).

### A brief explanation of how mom handles indents

Mom provides five kinds of indents: left, right, both, temporary, and hanging. Each is invoked by its own name:

- IL = Indent Left
- IR = Indent Right
- IB = Indent Both
- HI = Hanging Indent
- TI = Temporary Indent

In addition, there are four macros to control exiting from indents:

- IQ = quit all active indents
- ILX = exit indent style left
- IRX = exit indent style right
- IBX = exit indent style both

This section deals exclusively with IL, IR and IB. For an explanation of hanging and temporary indents -- how they work and how to use them -- see Hanging indents and Temporary indents.

The first time you invoke any of mom's indents, you must supply a measure. For example,

    	.IL 2P

indents text 2 picas from the left margin (or current tab indent).

When you want to exit the above indent, use either

    	.IQ
    	 or
    	.ILX

The next time you want the same indent, invoke it without the argument, like this:

    	.IL

As you can see, once you've supplied a measure to an indent macro mom stores the value, obviating the need to repeat it on subsequent invocations. And mom doesn't just store the measure -- she hangs on to it tenaciously. Arguments passed to IL, IR and IB are additive. Consider the following:

    	.LL 20P
    	.IR 2P    \"Indent right by 2 picas
    	A first block of text...
    	...
    	...
    	.IQ       \"Turn indent off
    	A second block of text...
    	...
    	...
    	.IR 2P    \"Indent right by an additional 2 picas (i.e. 4 picas)
    	A third block of text...
    	...
    	...

The first block of text is right indented by 2 picas (i.e. the line length is shortened by 2 picas to 18 picas). The second block of text, after IQ, is, as you'd expect, set to the full measure. The third block of text -- the one to pay attention to -- is not right indented by 2 picas, but rather by 4 picas. Mom adds the value of arguments to IL, IR and IB to whatever value is already in effect.

If you wanted the third block of text in the example above to be right indented by just 2 picas (the original measure given to IR), you would enter `.IR` without an argument.

Because indent arguments are additive, putting a minus sign in front of the argument can be used to subtract from the current value. In the following example, the first line is indented 18 points, the second is indented 36 points (18+18), and the third is again indented 18 points (36-18).

    	.IL 18p     \"Indent left by 18 points      = 18 points
    	Now is the time
    	.IL 18p     \"Indent left by 18 points more = 36 points
    	for all good men to come
    	.IL -18p    \"Indent left by 18 points less = 18 points
    	to the aid of the party.

Sometimes, you may want to clear out the stored indent values -- let mom start indenting with a clean slate, as it were. Giving the optional argument `CLEAR` to any of the "indent quit" macros resets them to zero.

- IQ CLEAR = quit and clear all indents
- ILX CLEAR = quit and clear indent style left
- IRX CLEAR = quit and clear indent style right
- IBX CLEAR = quit and clear indent style both

Indent styles may be combined and manipulated separately. You could, for example, have a left indent of 4 picas and a right indent of 6 picas and control each separately, as in the following example.

    	.IL 4P     \"Indent left 4 picas
    	.IR 6P     \"Indent right 6 picas
    	Some text
    	.IRX       \"Turn off the right indent only
    	More text  \"Text is still indented 4 picas left

If, at `.IRX`, you wanted the text afterward to have no indents (either left or right), you would enter `.IQ`, which exits all indent styles at once.

A word of advice: Indents are best used only when you have a compelling reason not to change the current left margin or line length. In many instances where indents might seem expedient, it's better to use tabs, or actually change the left margin or the line length. Mom's indenting macros are flexible and powerful, but easy to get tangled up in. Personally, I don't use them much, except for cutarounds and multi-level lists ŕ la html, at which they excel.

NOTE: see the section Typesetting Macros in Document Processing for information and advice on using idents with the document processing macros.

### Indents macro list

- IL (Indent left)
- IR (Indent right)
- IB (Indent both)
- TI (Temporary indent, left)
- HI (Hanging Indent)
  - A recipe for numbered lists
- IQ (Quit indents, all)
- ILX (Exit indent style left)
- IRX (Exit indent style right)
- IBX (Exit indent style both)

### Indent left

Macro: IL [ <measure> ]
*The optional argument requires a unit of measure

IL indents text from the left margin of the page, or if you're in a tab, from the left edge of the tab. Once IL is on, the left indent is applied uniformly to every subsequent line of text, even if you change the line length.

The first time you invoke IL, you must give it a measure. Subsequent invocations with a measure add to the previous measure. A minus sign may be prepended to the argument to subtract from the current measure. The \w inline escape may be used to specify a text-dependent measure, in which case no unit of measure is required. For example,

    	.IL \w'margarine'

indents text by the width of the word "margarine".

With no argument, IL indents by its last active value. See the brief explanation of how mom handles indents for more details.

NOTE: Calling a tab (with TAB) automatically cancels any active indents.

ADDITIONAL NOTE: Invoking IL automtically turns off IB.

### Indent right

Macro: IR [ <measure> ]
*The optional argument requires a unit of measure

IR indents text from the right margin of the page, or if you're in a tab, from the end of the tab.

The first time you invoke IR, you must give it a measure. Subsequent invocations with a measure add to the previous indent measure. A minus sign may be prepended to the argument to subtract from the current indent measure. The \w inline esacpe may be used to specify a text-dependent measure, in which case no unit of measure is required. For example,

    	.IR \w'jello'

indents text by the width of the word "jello".

With no argument, IR indents by its last active value. See the brief explanation of how mom handles indents for more details.

NOTE: Calling a tab (with TAB) automatically cancels any active indents.

ADDITIONAL NOTE: Invoking IR automtically turns off IB.

### Indent both

Macro: IB [ <left measure> <right measure> ]
*The optional arguments require a unit of measure

IB allows you to set or invoke a left and a right indent at the same time.

At its first invocation, you must supply a measure for both indents; at subsequent invocations when you wish to supply a measure, both must be given again. As with IL and IR, the measures are added to the values previously passed to the macro. Hence, if you wish to change just one of the values, you must give an argument of zero to the other.

A word of advice: If you need to manipulate left and right indents separately, use a combination of IL and IR instead of IB. You'll save yourself a lot of grief.

A minus sign may be prepended to the arguments to subtract from their current values. The \w inline esacpe may be used to specify text-dependent measures, in which case no unit of measure is required. For example,

    	.IB \w'margaraine' \w'jello'

left indents text by the width of the word "margarine" and right indents by the width of "jello".

Like IL and IR, IB with no argument indents by its last active values. See the brief explanation of how mom handles indents for more details.

NOTE: Calling a tab (with TAB) automatically cancels any active indents.

ADDITIONAL NOTE: Invoking IB automtically turns off IL and IR.

### Temporary (left) indent

Macro: TI [ <measure> ]
*The optional argument requires a unit of measure

A temporary indent is one that applies only to the first line of text that comes after it. It's chief use is indenting the first line of paragraphs. (Mom's PP macro, for example, uses a temporary indent.)

The first time you invoke TI, you must give it a measure. If you want to indent the first line of a paragraph by, say, 2 ems, do

    	.TI 2m

Subsequent invocations of TI do not require you to supply a measure; mom keeps track of the last measure you gave it.

Because temporary indents are temporary, there's no need to turn them off.

IMPORTANT: Unlike IL, IR and IB, measures given to TI are NOT additive. In the following example, the second `.TI 2P` is exactly 2 picas.

    	.TI 1P
    	The beginning of a paragraph...
    	.TI 2P
    	The beginning of another paragraph...

### Hanging indent

Macro: HI [ <measure> ]
*The optional argument requires a unit of measure

A hanging indent looks like this:

    	The thousand injuries of Fortunato I had borne as best I
    	    could, but when he ventured upon insult, I vowed
    	    revenge.  You who so well know the nature of my soul
    	    will not suppose, however, that I gave utterance to a
    	    threat, at length I would be avenged...

The first line of text "hangs" outside the left margin.

In order to use hanging indents, you must first have a left indent active (set with either IL or IB). Mom will not hang text outside the left margin set with L_MARGIN or outside the left margin of a tab.

The first time you invoke HI, you must give it a measure. If you want the first line of a paragraph to hang by, say, 1 pica, do

    	.IL 1P
    	.HI 1P

Subsequent invocations of HI do not require you to supply a measure; mom keeps track of the last measure you gave it.

Generally speaking, you should invoke HI immediately prior to the line you want hung (i.e. without any intervening control lines). And because hanging indents affect only one line, there's no need to turn them off.

### A recipe for numbered lists

A common use for hanging indents is setting numbered lists. Consider the following example:

    	.PAGE 8.5i 11i 1i 1i 1i 1i
    	.FAMILY  T
    	.FT      R
    	.PT_SIZE 12
    	.LS      14
    	.JUSTIFY
    	.KERN
    	.SS 0
    	.IL \w'\0\0.'    \"Indent left by 2 figure spaces and a period
    	.HI \w'\0\0.'    \"Hang first line of text back by 2 figure spaces and a period
    	1.\0The most important point to be considered is whether the
    	answer to the meaning of life, the universe, and everything
    	really is 42.  We have no-one's word on the subject except
    	Mr. Adams'.
    	.HI
    	2.\0If the answer to the meaning of life, the universe,
    	and everything is indeed 42, what impact does this have on
    	the politics of representation?  42 is, after all not a
    	prime number.  Are we to infer that prime numbers don't
    	deserve equal rights and equal access in the universe?
    	.HI
    	3.\0If 42 is deemed non-exclusionary, how do we present it
    	as the answer and, at the same time, forestall debate on its
    	exclusionary implications?

First, we invoke a left indent with a measure equal to the width of 2 figures spaces plus a period (using the \w inline escape). At this point, the left indent is active; text afterward would normally be indented. However, we invoke a hanging indent of exactly the same width, which hangs the first line (and first line only!) to the left of the indent by the same distance (in this case, that means "out to the left margin"). Because we begin the first line with a number, a period, and a figure space, the actual text ("The most important point...") starts at exactly the same spot as the indented lines that follow.

Notice that subsequent invocations of HI without a measure produce exactly the same effect.

Paste the example above into a file and preview it with `groff -mom -X <filename>` to see hanging indents in action.

IMPORTANT: Unlike IL, IR and IB, measures given to HI are NOT additive. Each time you pass a measure to HI, the measure is treated literally.

### Quitting indents

Macro: IQ [ CLEAR ] (quit any/all indents -- see *IMPORTANT NOTE)
Macro: ILX [ CLEAR ] (exit Indent Left)
Macro: IRX [ CLEAR ] (exit Indent Right)
Macro: IBX [ CLEAR ] (exit Indent Both)

*IMPORTANT NOTE:
Formerly, the macro for quitting all indents was .IX. This usage is now deprecated, in favour of .IQ. .IX will continue to behave as before, but mom will issue a warning to stderr indicating that you should update your documents.
As a consequence of this change, ILX, IRX and IBX may now also be invoked as ILQ, IRQ and IBQ. Both forms are acceptable.

Without an argument, the macros to quit indents merely restore your original left margin and line length. The measures stored in the indent macros themselves are saved so you can call them again without having to supply a measure.

If you pass these macros the optional argument CLEAR, they not only restore your original left margin and line length, but also clear any values associated with a particular indent style. The next time you need an indent of the same style, you have to supply a measure again.

IQ CLEAR, as you'd suspect, quits and clears the values for all indent styles at once.

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