No spamming. No solicitation. No astroturfing. No advertise about your company/blog/product without explicit consent. Instant ban for any of the following
2
Respect NDAs
Do not post anything proprietary, confidential, etc.
3
Do your own homework
There is a difference between asking for help after doing your due diligence vs asking someone to do your own homework. Asking the community to come up with your PhD/Masters thesis/project is NOT acceptable.