Manual:$wgFilterCallback

Details
Similar to $wgSpamRegex, you can get a function to do the job. The function will be given the following args:


 * 1) a Title object for the article the edit is made on
 * 2) the text submitted in the textarea (wpTextbox1)
 * 3) the section number.

The return should be boolean indicating whether the edit matched some evilness:


 * true : block it
 * false : let it through

For a complete example, have a look at the Extension:SpamBlacklist source code.