I've found that some of the Markup codes interfere with normal posting, such as when i try to say "Nonoba", the chat room, it italicizes the "a" instead of surrounding it with slash marks, as intended. To fix this, you should either implement another markup language (such as taking the bracket tags from BBCode) or add in an escape character (such as \) that when placed in front of a markup character will make that character's literal form appear instead of the markup form.