Comments should get more thoughtful and substantive,
  not less, as a topic gets more divisive.

  Eschew flamebait. Avoid generic tangents. Omit internet
  tropes.

  Be kind. Don't be snarky. Converse curiously;
  don't cross-examine. Edit out swipes.

  Please don't comment about the voting on comments.
  It never does any good, and it makes boring reading.

HTH