Firstly, be nice to others; do not attack others in the group.
Using welcoming and inclusive language. It is better to be kind than clever.
Respect different viewpoints and place your opinions constructively.
Help others wherever your expertise lends itself well. This is the primary objective of the community.
Obvious, but explicitly stated policies:
Do not spam, post or link to content that is abusive, hateful, offensive or sexually explicit
Do not post or link to content that threatens or harasses others
Do not post any material that violates the copyrights or other intellectual property rights of others