<p>Comments belong to a thing. Comments on a photo or video or blog post should be about that thing. Don't post "hey what's up?", "let's hang out", "do you have ricky's phone number?", etc. Send a message with that. </p>

<p>If you don't have the ability to comment on a thing directly (say your replying to a tweet of mine that is not the newest), give some context. </p>