Respect is the minimum.

This is a members-only  discussion, not a debate. The purpose is not to win an argument, but to hear many points of view and explore many options and solutions.
Everyone is encouraged to participate. 
No two individuals should dominate a discussion, unless there are only two participants. When you comment, be brief and to the point.
Do your best to understand the pros and cons of every option, not just those you prefer. Be as objective and fair-minded as you can be.
Seek first to understand, not to be understood. Ask questions to seek clarification when you don't understand the meaning of someone's comments.