A stubborn self-promoter/spammer used to use http://www.lovifm.com so I set up a SpamBlacklist's rule . But he got smarter and started to use http://www.ℒoviℱm.com instead, which also is a valid URL. I modified existing rule to \b[lℒ]ovi[fℱ]m\.com\b but it doesn't catch the second URL.

BTW. Please note how Phabricator renders second URL. MediaWiki does it properly.