Maybe above the chat box we could have a few ground rules. such as:
#1 - Most importantly, keep it civil and don't be rude. It's easy to misinterpret others on the internet. Relax, be nice, and you'll find everyone else is too.
#2 - Please avoid spamming. This includes one word answers, continual irrelevant and general nonsensical talk. Read and think carefully before you post.
#3 - Double or triple posting should be avoided. You may reply your own post after 24 hours have passed. If not, then use the EDIT button to update it.
#4 - Constructive criticism is a must. But please be thoughtful of others and understand that people aren't trying to constantly demotivate you.
#5 - No Racist, sexist, homophobic or religious talk. I need say no more.
#6 - Don't post OR link to anything pornographic, disgusting, gory, or illegal (including illegal file sharing). Keep it to yourself.
This is just an example from another site I frequent.