What methods do you use to filter out spam on forums and in comments to publications?

Question

PHP

Hello.
What methods do you use to filter out spam on forums and in comments to posts on your sites/projects? (PHP language)
What kind of spam content are you interested in filtering out?
1. advertising, calls to go to sites (without links!),
2. links to third-party resources (URL links in explicit and implicit form: for example, through fictitious separators),
3. profanity (mother-to-mother),
4. useless/chaotic set of characters/characters (text without meaning) - API
5. many punctuation marks or other characters that go in a row inside the text (when it is impossible to do normalization)
Do you use any libraries (for example, from github) or similar, or do you use something else?
In advance, thank you all for your replies!

Answer 1

On a project where N orders come in, we use a number of algorithms to filter orders, phone number, stop words in full name, checking public proxy databases.
You can do the same for other cases :)