Do not.

  • Edit other user pages besides your own without permission.
  • Create new categories without asking an admin first.
  • Post false information
  • Insult/use bad language with other users. If this happens, you should get a warning message on your wall.
  • Harrass/threaten another user
  • Create articles to advertise wikis or products. You can do that in blog posts. Doing it in articles is considered spamming.
  • Remove content from pages you dislike. That's called vandalism.
  • Remove all the content from one page that is not spam etc. without an admin's permission.