OT: How to mark posts appropriately

[Guest guest]

I know a new topic gets a new subject, a reply has RE: before it, off

topic is OT:, and forwarded messages have FW:, but what do the

brackets [ ] and single bracket ] mean? Any other symbols?

And as a refresher, please post the general issues that are on or off

topic (I don't want to make a mountain out of a molehill, but the

home page makes it seem like anything goes). I am guessing that

therapies are off topic, baking tips are on, IEPs are off,

supplements are on. Is there a rough way to tell when an initial

request becomes off topic?

Thank you.