100319 Anomaly:Method - Unusual HTTP Method?

I’m interested in Managed Ruleset 100319, titled “Anomaly:Method Unusual HTTP Method”. I’m wondering if what http methods are included and if that simply fires based on the http methods and nothing more.

Also, is there a way to get a description of these rulesets? It’s possible (but not super easy) to get descriptions for the OWASP ones since they’re public but I can’t find anything on the Cloudflare Specials ones.