... but ...
The testsuite should have also included markup which must not be replaced
My fault sorry, I thought it's obvious by the $pre and $post regex.
The markup must come in pairs and be embraced by special word boundaries.
(whitespace or other markup or tag-brackets or ... depending on pre/post)
Hence a _ inside a word is forbidden, which makes sense for joined_identifiers .
I've updated the tests in Re: wiki regex reprocessing replacement (UPDATED^2) with markup to ignore
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery