"modifying another’s post in order to cast him/her in a bad light is a sufficient, but not necessary condition to trigger a violation of this rule. Parsed accurately, the rule states that:
Falsely attributing a quote to another user; or
Modifying another’s post in order to cast him/her in a bad light
Are grounds for sanction.
There is also a prohibition on adding editorial comments to quote boxes or editing it to change the meaning.