General principles for customization

Style files and packages basically enrich the current typesetting environment with a combination of

• Environment variables.
• Tags for the end-user.
• Customizable macros.

Furthermore, they may define some tags for intern implementation purposes, which will not be documented in this manual. They may also specify some logical properties of tags using the drd-props primitive.

Environment variables are almost always attributes for controlling the rendering of content, or counters for sections, equations, etc.. Although several simple tags for the end-user like strong may be redefined in your own style files, this practice is not recommended for more complex tags like section. Indeed, the section tag involves many things like resetting subcounters, entering the title into the table of contents and so on. Therefore, special additional macros are provided the customization of such tags, like section-title, section-clean and section-toc.