WHAT IS A “POOR-MAN'S COPYRIGHT”?

A poor man’s copyright is an old concept designed to serve as proof of when you created an idea.  A person writes down his invention and puts it in the mail, addressing it to himself.  Once received, it is left unopened.  The envelope is dated by the post office, thus proving that it was created by that date.  However, the law gives no effect to a “poor man’s copyright” and this action gives you no protection over your intellectual property.