If you use RCS or CVS to maintain your (La)TeX documents under version control, you may need some mechanism for including the RCS keywords in your document, in such a way that they can be typeset (that is, rather than just hiding them inside a comment).
The most complete solution is to use the (LaTeX) package rcs, which allows you to parse and display the contents of RCS keyword fields in an extremely flexible way. The package rcsinfo is simpler, but does most of what you want, and some people prefer it; it is explicitly compatible with LaTeX2HTML.
If, however, you need a solution which works without using external packages, or which will work in plain TeX, then you can use the following minimal solution:
\def\RCS$#1: #2 ${\expandafter\def\csname RCS#1\endcsname{#2}}
\RCS$Revision: 1.267 $ % or any RCS keyword
\RCS$Date: 2005/01/05 10:24:43 $
...
\date{Revision \RCSRevision, \RCSDate}
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