on Writer Beware site:

SFWA’s Contracts Committee has recently been seeing a proliferation of contracts from small magazines, and a very few established markets, that license all derivative rights in perpetuity.

This is a red flag for a number of reasons, even if these rights are licensed non-exclusively.

A derivative work is defined by copyright law as “a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted.”

This sort of rights grab is by no means normal; magazines generally only take very limited first publication and archival rights for a limited time.

Licensing the right to create derivative works can and mostly likely will interfere with the author’s right to exploit their right to create or license derivative works to…