flex-old-doc - 2.5.4a-10.1 main

This package contains the HTML documentation for the old 2.5.4a version
of flex, which is no longer being developed upstream. You should
normally chose flex-doc, unless you have legacy lexer files that do
not work with a modern flex, and need to use the old flex. The
upstream source code can be found at the FTP site:
http://flex.sourceforge.net/