Years ago I worked inside Akismet - https://akismet.com - which is an Automattic product.

Akismet, along with user chosen comment moderated lists in 'Comments > Discussion' would not publish certain comment content.

For example, you put 'bad' in to your moderation list and if someone wrote 'badger' your comment was moderated, and probably deleted.

Various sites had "Copy this Bad Words List"

There was/is a medication called cialis

Lots of spam - email, web, comment, used those 6 letters

There was a HUGE amount of comments caught that used socialist, socialism in the US elections.