In the past I've used a trap unicode character in a name in a public wiki-style CC-BY licensed database of politicians to confirm that a site was (not malicious

In the past I've used a trap unicode character in a name in a public wiki-style CC-BY licensed database of politicians to confirm that a site was (not maliciously) failing to credit us. This resulted in the person who was using our data reverting the unicode character edit in our database, probably because it was breaking their import scripts.