foo

Works for me with Lemmy-UI. I'm guessing whatever client/browser you're using is including the period at the end of the sentence in the URL.

I suppose you could argue an "illegal number" is: https://en.wikipedia.org/wiki/Illegal_number.

For example, the HD DVD encryption key saga was originally fought via DMCA notices to Digg: https://en.wikipedia.org/wiki/AACS_encryption_key_controversy