Conditionally Visible Text
**************************
Sometimes it is good to use different text for different output
formats. For example, you can use the "conditional commands" to specify
different text for the printed manual and the Info output.
Conditional commands may not be nested.
The conditional commands comprise the following categories.
* Commands for HTML, Info, or TeX.
* Commands for not HTML, Info, or TeX.
* Raw TeX or HTML commands.
* Substituting text for all formats, and testing if a flag is set or
clear.