man.charmap.use.subset boolean
man.charmap.use.subset Use subset of character map instead of full map?

## Description

If the value of the man.charmap.use.subset parameter is non-zero, a subset of the roff character map is used instead of the full roff character map. The profile of the subset used is determined either by the value of the man.charmap.subset.profile parameter (if the source is not in English) or the man.charmap.subset.profile.english parameter (if the source is in English).

You may want to experiment with setting a non-zero value of man.charmap.use.subset, so that the full character map is used. Depending on which XSLT engine you run, setting a non-zero value for man.charmap.use.subset may significantly increase the time needed to process your documents. Or it may not. For example, if you set it and run it with xsltproc, it seems to dramatically increase processing time; on the other hand, if you set it and run it with Saxon, it does not seem to increase processing time nearly as much.

If processing time is not a important concern and/or you can tolerate the increase in processing time imposed by using the full character map, set man.charmap.use.subset to zero.

### Details

For converting certain Unicode symbols and special characters in UTF-8 or UTF-16 encoded XML source to appropriate groff/roff equivalents in man-page output, the DocBook XSL Stylesheets distribution includes a roff character map that is compliant with the XSLT character map format as detailed in the XSLT 2.0 specification. The map contains more than 800 character mappings and can be considered the standard roff character map for the distribution.

You can use the man.charmap.uri parameter to specify a URI for the location for an alternate roff character map to use in place of the standard roff character map provided in the distribution.

Because it is not terrifically efficient to use the standard 800-character character map in full -- and for most (or all) users, never necessary to use it in full -- the DocBook XSL Stylesheets support a mechanism for using, within any given character map, a subset of character mappings instead of the full set. You can use the man.charmap.subset.profile or man.charmap.subset.profile.english parameter to tune the profile of that subset to use.