I use several different namespaces to separate the content by type.
| xmlns | Content/Purpose |
|---|---|
| d20 | Gaming/business domain objects (data). |
| doc | Document structure (headings, tables, paragraphs, etc.). |
| dot | Information to feed into GraphViz ‘dot’ program (formatting hints, etc.). |
| egd | Process and publisher-related things, regardless of domain (document or business). Metadata and utilities, mostly. |
| meta | Metadata about objects, mostly contained in egd:meta elements. |
| pgf | Information to feed into PGF/TikZ diagrams (formatting hints, etc.). |
| tax | Taxonomy elements used to define business objects. |
| tex | Information to feed into LaTeX processing. |
| web | Information to feed into web formatting. Not using HTML because I reserve that specifically for HTML markup. |