Configuration files, including centralized catalogs.
It includes:
| *.conf: generic configuration files |
| sgml-docbook.cat, tei.cat, ...: DTD-specific centralized catalogs |
| catalog: the super catalog |
| ... |
Architecture-independent files used by SGML/XML computer programs: Open Catalogs (not the centralized ones), DTDs, entities, style sheets, and other declarative files, if any.
It is organized into DTD-specific subdirectories:
| docbook/ |
| tei/ |
| html/ |
| ... |
Data that are not DTD-specific go directly into /usr/share/sgml, preferably under their own directory.
At least for the present, all XML documents are also SGML documents, so it seems unnecessary to create /usr/share/xml and /etc/xml.