Fuzzy Matching
==============
Gnus provides "fuzzy matching" of `Subject' lines when doing things
like scoring, thread gathering and thread comparison.
As opposed to regular expression matching, fuzzy matching is very
fuzzy. It's so fuzzy that there's not even a definition of what
"fuzziness" means, and the implementation has changed over time.
Basically, it tries to remove all noise from lines before comparing.
`Re: ', parenthetical remarks, white space, and so on, are filtered out
of the strings before comparing the results. This often leads to
adequate results--even when faced with strings generated by text
manglers masquerading as newsreaders.