MWG Tags

## MWG Composite Tags

This table lists special Composite tags which are used to access other tags based on the Metadata Working Group 1.01 recommendations. These tags are only accessible when the MWG module is loaded (via `-use MWG` on the command line, or `use Image::ExifTool::MWG` in the API). When reading, the value of each MWG tag is Derived From the specified tags based on the MWG guidelines. When writing, the value of the IPTCDigest tag is updated automatically when the IPTC is changed if either the IPTCDigest tag didn't exist beforehand or its value agreed with the original IPTC digest (indicating that the XMP is synchronized with the IPTC). IPTC information is written only if the original file contained IPTC. For more information about the MWG recommendation, see http://www.metadataworkinggroup.org/.

Loading the MWG module activates "strict MWG conformance mode", which has the effect of causing EXIF, IPTC and XMP in non-standard locations to be ignored when reading, as per the MWG recommendations. Instead, a "Warning" tag is generated when non-standard metadata is encountered. This feature may be disabled by setting `$Image::ExifTool::MWG::strict = 0` in the ExifTool config file (or from your Perl script when using the API). Note that the behaviour when writing is not changed: ExifTool always creates new records only in the standard location, but writes new tags to any EXIF/IPTC/XMP records that exist.

A complication of the specification is that although the MWG:Creator property may consist of multiple values, the associated EXIF tag (EXIF:Artist) is only a simple string. To resolve this discrepancy the MWG recommends a technique which allows a list of values to be stored in a string by using a semicolon-space separator (with quotes around values if necessary). When the MWG module is loaded, ExifTool automatically implements this policy and changes EXIF:Artist to a list-type tag.

> Tag Name | Writable | Derived From | Values / Notes
> --- | --- | --- | ---
> City | Y | IPTC:City XMP-photoshop:City CurrentIPTCDigest IPTCDigest |
> Copyright | Y | EXIF:Copyright IPTC:CopyrightNotice XMP-dc:Rights CurrentIPTCDigest IPTCDigest |
> Country | Y | IPTC:Country-PrimaryLocationName XMP-photoshop:Country CurrentIPTCDigest IPTCDigest |
> CreateDate | Y | EXIF:CreateDate EXIF:SubSecTimeDigitized IPTC:DigitalCreationDate IPTC:DigitalCreationTime XMP-xmp:CreateDate CurrentIPTCDigest IPTCDigest | ("creation date of the digital representation" - MWG)
> Creator | Y+ | EXIF:Artist IPTC:By-line XMP-dc:Creator CurrentIPTCDigest IPTCDigest |
> DateTimeOriginal | Y | EXIF:DateTimeOriginal EXIF:SubSecTimeOriginal IPTC:DateCreated IPTC:TimeCreated XMP-photoshop:DateCreated CurrentIPTCDigest IPTCDigest | ("creation date of the intellectual content being shown" - MWG)
> Description | Y | EXIF:ImageDescription IPTC:Caption-Abstract XMP-dc:Description CurrentIPTCDigest IPTCDigest |
> Keywords | Y+ | IPTC:Keywords XMP-dc:Subject CurrentIPTCDigest IPTCDigest |
> Location | Y | IPTC:Sub-location XMP-iptcCore:Location CurrentIPTCDigest IPTCDigest |
> ModifyDate | Y | EXIF:ModifyDate EXIF:SubSecTime XMP-xmp:ModifyDate CurrentIPTCDigest IPTCDigest | ("modification date of the digital image file" - MWG)
> Orientation | Y | EXIF:Orientation | 1 = Horizontal (normal) 2 = Mirror horizontal 3 = Rotate 180 4 = Mirror vertical 5 = Mirror horizontal and rotate 270 CW 6 = Rotate 90 CW 7 = Mirror horizontal and rotate 90 CW 8 = Rotate 270 CW
> Rating | Y | XMP-xmp:Rating |
> State | Y | IPTC:Province-State XMP-photoshop:State CurrentIPTCDigest IPTCDigest |

(This document generated automatically by Image::ExifTool::BuildTagLookup)
Last revised Mar 4, 2010

<-- ExifTool Tag Names