I'm sorry to have to say this, but people responding so far have seemed unable to comprehend my simple question and answer it. I've seen a patronizing lecture on what copyright is, advice on a writing career, etc.

So I've searched on my own. (I checked several sites plus copyright.gov.)

Yes, an author is protected by copyright as soon as a work is created in tangible/perceptible form. But that protection is dependent. If s/he has no irrefutable proof that s/he wrote it first, including no agreement (yet) with the publisher, someone else (e.g. editor) who gets his/her ideas and publishes them first has a much better case that the copyright is theirs. This is couched with the suspicion that the editor could claim any emails are just forged.

My question was simple: What is the mechanism that an author has to establish that prima facie evidence to prevent this? ANSWERS I'VE FOUND:

1. Registration with the U.S. Copyright Office is one such form of evidence of the validity of the copyright by the author. But it's costly ($35) if you're writing many things, and is somewhat inconvenient.

2. A notarized copy would work I guess.

3. Mailing a sealed copy to oneself probably helps a little, if it's postmarked. And I imagine having a witness would help. But I doubt they're a sure thing.

It's odd that nodoby here could just say what you do. Grant said to just rely on the integrity of the publication. Is that it?