Thread:Project:Support desk/How can I prevent removal of certain wikitext from pages with Abuse Filter?/reply (3)

I was looking through some of the filters on other wikis, and I haven't learned enough from it to write filters. Are there any good guides? There was a filter I saw to prevent posting email addresses, which could be useful for preventing meatpuppetry and other coordinated forms of misuse and harassment. It was set as private though.