Recently, I heard chatter about this on a listserve, so I updated my research on this topic and am sharing it here.
One of the biggest flaws of this idea is that the postmark and seal prove something.
- What is to prevent someone from mailing an UNsealed envelope to themselves? It has a postmark. But since it is unsealed, material can be placed in it at any time--2 months later, 2 years later, 10 years later, then sealed.
- Sealed envelopes can be steamed open (and probably opened by many other methods that I don't know), the material replaced with something else, then resealed.
Read what the copyright office itself has to say at www.copyright.gov. The Frequently Asked Questions page is very helpful resource. This page has "Copyright Registration of Books, Manuscripts, and Speeches."
A book recommended by the Author's Guild is The Writer's Legal Guide by Tad Crawford & Kay Murray. It is in its fourth printing.
Here are some articles and a transcript on this topic:
"Poor Man's Copyright" by Peter Clarke
"Poor Man's Copyright" by ©opyright Authority.com
"How To Copyright a Book" at Go-Publish-Yourself.com begins with this sentence: "Before learning how to copyright a book, you need to learn how not to copyright book."
Intellectual property lawyer Linda Joy Kattwinkel talked a lot about copyright in this chat on the ICL website.
Want to know more?
Some authors may want to consider an intellectual property rights lawyer. I found some information on copyrights here at intellectual-property.lawyers.com. Here's an interesting post with a Literary Agent Attorney FAQ from Literary-Agents.com.
So now you know--poor man's copyright, only a myth.