<filepath>configuration.properties</filepath> file The lib/configuration.properties file controls certain common properties, as well as some properties that control PDF processing. configuration properties default.language generate-debug-attributes processing-mode org.dita.pdf2.i18n.enabled org.dita.pdf2.use-out-temp files lib/configuration.properties file topic.fo file topic.fo location of PDF processing configuration properties
Properties set in the <filepath>lib/configuration.properties</filepath> file default.language Specifies the language that is used if the input file does not have the xml:lang attribute set on the root element. By default, this is set to . The allowed values are those that are defined in IETF BCP 47, Tags for Identifying Languages. org.dita.pdf2.i18n.enabled (PDF transformation only) Enables I18N font processing. The following values are allowed:
  • (default) — Enables I18N processing
  • — Disables I18N processing
This needs beefing up. Here is info provided by Jarno Elovirta:

(IIRC, pre 1.0 versions of FOP didn't correctly implement font selection in XSL FO files, that's the reason for this feature existing). The PDF2 I18N allows you to say define which characters are output with which pseudo-font, and the font mapping files define the actual font. E.g. the configuration for English at src/main/plugins/org.dita.pdf2/cfg/fo/i18n/en.xml is: <alphabet char-set="SymbolsSuperscript"> <character-set> <!-- Copyright --> <character>&#169;</character> <!-- Registered Trademark --> <character>&#174;</character> <!-- Trademark --> <character>&#8482;</character> <!-- Service mark --> <character>&#2120;</character> </character-set> </alphabet> <alphabet char-set="SubmenuSymbol"> <character-set> <character>&#x27A4;</character> </character-set> </alphabet>

That is, those specific characters are marked as "SymbolsSuperscript" or "SubmenuSymbol" charset. The font mappings at src/main/plugins/org.dita.pdf2/cfg/fo/font-mappings.xml then define which font to use for them, e.g.:<physical-font char-set="SymbolsSuperscript"> <font-face>Helvetica, Arial Unicode MS</font-face> <baseline-shift>20%</baseline-shift> <override-size>smaller</override-size> </physical-font>

The I18N processing is on by default (because it's been on before), but for most users it's just an additional level of complexity which should be turned off and support for multiple languages be handled in XSLT code.

 plugindirs A semicolon-separated list of directory paths that the DITA-OT searches for plug-ins to install; any relative paths are resolved against the DITA-OT base directory. Any immediate subdirectory that contains a plugin.xml file is installed. plugin.ignores A semicolon-separated list of directory names to be ignored during plug-in installation; any relative paths are resolved against the DITA-OT base directory.