How can I tell if a comment was made by a moderator?
On MetaFilter and AskMetafilter, moderators use small type and square brackets to indicate they are making an "official" comment:
[Mod comments look like this.]
Moderators are also regular users of the site, and they also participate in threads in a non-official capacity. If you're not sure how a specific mod comment is meant, ask using the contact form. If you're not sure if someone is a moderator, see the list of moderators here.
On MetaTalk, moderators are identified by a little "staff" badge next to their username. The staff badge is always "on" in MetaTalk.