How old before answer is impolite?

I have just registered to be able to post messages.

How far back can I go before a reply seems to be inapropriate?

There are some old messages that I may be able to offer a useful opinion on.

Thanks.

About a month is acceptable. If you have a comment on an older thread, it is recomended you post a new thread in the same forum with your comment and provide a link to the thread to which you are referring.

Also, threads asking about the message board, and its ettiquette belong in About This Message Board.

If your answer is just a confirmation of something already in the thread, probably best to let it be. If it’s truly new information and helpful to the OP, the bottom of the forum is the limit! (That said, stuff from more than a couple years ago is pretty much unreadable because of a bad conversion experience we had, so you may want to stick to the newer stuff).

Welcome to the Straight Dope Message Boards!

Since this question would apply in more than one forum, I’ll move it to About This Message Board.

Oh, forgot to mention – when you bring up an older thread, it may help to preface your answer with something like “I know this is an old one, but…” That will help people realize that it’s been brought back from the bottom of the pile.

Read the FAQ threads in this forum. For example, the question you asked was answered here.

You will note that there are contradictory directions here.

The guidelines about bumping your old post up to the top is pretty much as referenced in the FAQ that Arnold gave as a link.

In terms of adding something to old posts, the guidelines aren’t hard and fast. QED says a month, manhattan says whenever but not too old, and Arnold’s FAQ says three months. I think it varies by forum and by topic and by what you’re really adding, but three months is the formal “guide.”