You might want to ask around at the spam tools mailing list. I used to read it religiously when I was responsibe for maintaining spam filters.

I'm guessing someone's probably already done what you describe. If they haven't, I would probably handle it like soundex, but instead of grouping letters that sound like, grouping glyphs that look alike. (note, I specifically didn't say try to get them to the 'right' value, because the (0Oo) and (1lIi) distinctions are context sensitive ... (100K! M3ds @ lO% 0ff!), and the true meaning doesn't really matter, unless you're trying to determine if it's intentionally obfuscated, as opposed to just a suspicious keywords.)

Oh... and UTF is going to make for a very, very large set of glpyhs.

In reply to Re: Spam filtering and regular expressions by jhourcle
in thread Spam filtering and regular expressions by Mr. Lee

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