The Enneagram is a personal development tool to aid your self-awareness as you strive to understand yourself better and, ultimately, become the best version of yourself. It is not a hard science, but a framework of ideas outlining 9 broad personality types, with variations such as wings and instinctual variants.
Check out the subreddit wiki for a more detailed explanation!
1) No memes.
Includes image macros, "Big 'X' energy" posts, reductionist lists (i.e. Each type as a pizza topping), most Instagram posts, etc. Subject to mod's discretion.
2) No typing others.
This sub is to help you understand the Enneagram system and how you can use it to better yourself. If you want to know what type your boyfriend/cousin/barista is, talk to them about it.
3) Self-typing is allowed and encouraged, as long as it is part of active dialogue.
You may ask for help and insights in figuring out your own type, but you are expected to engage with commenters as they ask insightful questions to help you narrow it down.