Well, only one entity at a time can own the copyright (of course one could probably arange joint ownership, but that's not what's usually meant with copyright assignment). After all, the point of copyright is to apply to *all* copies, including copies that other people make.
The FSF procedure is that copyright is assigned to FSF, and in return the original author gets the right¹ to use the code in any way he or she please. But the copyright is owned by the FSF. If you want cpyright to be owned by both IDA and the FSF, I'm not sure how to arrange that.
-- ¹ Recent versions of the form seems to require 30 days prior written notice before taking advantage of that.
/ Niels Möller ()
Previous text:
2002-11-11 19:04: Subject: Re: pike.el
It's two diffrent copies. You (explicitly as should be stated on the www-page, but I'm writing this in an AIDO-TTY, so I can't check) retain rights to use code you wrote under whatever license you choose barring the normal restrictions. FSF has something similar, but Niels probably has a better better idea of how that one works since he is the only person know that had the patience to go through the FSF-paperwork.
/ Peter Bortas