Non-Dialogue Quotation Marks and How to Punctuate Them

I have heard that rule about punctuating outside the quotation marks. I continue to do it your way in cases like this. Expect some argument.

You punctuate it as if someone, a character or the first person protagonist, is reading it aloud.

You're writing a work of fiction. Do you intend to get it published? If you do, publishers employ people called editors. Answering question such as this if one of the functions of editors. I have noticed some truly low standards in the quality of editing i have seen, so you might have to bring it specifically to the attention of your editor, should you ever be fortunate enough to have an editor. There are also such things as style manuals. I suggest that your first step should be to consult a style manual. Academic style manuals can safely be ignored--after the MLA, for example, does not publish short stories. The Chicago Manual of Style is a very well-known and trusted publication. Please note thae although there is a free trial, they would expect you to pay to use their service regularly, just as they would expect you to by it in book form, rather than stealing it.

This is an online style manual i found in seconds with a web search. Does it answer your question? I don't know--there's only so much i'll do for you, and holding your hand is not one of them.

A plaque on a door that reads, Maintenance. Why do you need quotation marks?

I knocked on the door that said Maintenance and went in.

A door that speaks? Straight out of Philip K Dick!

Whether to quote up material when describing indications of gauges, meters, computer dialogs and alerts, notices, signs, etc, is, as Setanta pointed out, a matter of style. Generally anything more formal in style than an text message will have quotes. Punctuation will only be within the quotes if it is actually contained within the matter quoted. Aspects of appearance such as case are usually faithfully reproduced.

OMFG my gas says empty.

I put up a sign which read "SMOKING IS FORBIDDEN".

The doormat reads "Welcome".

Look for a sign reading "STOP!".

It is slightly colloquial to write that notices and signs "say" things.

Thanks for clarifying that.

The demon that makes one commit errors when purporting to correct others was successful there...