From Grist’s posting rules on comments:
1. Don’t be a jerk. Nobody likes jerks.
2. Don’t use profanity. The English language is vast and magnificent.
3. Don’t be a troll. (Troll: Commenter who makes outrageous or provocative statements purely in order to derail discussion.) You know who you are.
4. No spam, no solicitation, no links to porn, no internet detritus of similar ilk. Sell us on your point of view, not your Super-Slanket!
5. No personal attacks at the author or fellow commenter. Substance, people. Substance.
6. Seriously, don’t be a jerk.