     Syntax: bf(%baseclass-preinclude) tt(pathname)

tt(Pathname) defines the path to the file preincluded in the parser's
base-class header.  See the description of the
link(--baseclass-preinclude)(PREINCLUDE) option for details about this
directive.

    By default `pathname' is surrounded by double quotes; but the double
quotes can also explicitly be specified.  When the argument is surrounded by
em(pointed brackets) tt(#include <header>) is used.
