If you are submitting to festivals, read the fine print. I have come across two festivals in the last month that not only want your submission fee, but then claim the worldwide, perpetual right to do anything they want with your film. I have complained to FilmFreeway about this, but nothing happened. See if you can find an article from The Hollywood Reporter from a few years ago about festivals like the Oaxaca Film Festival.
My films have shown in about 30 festivals worldwide, I have had great fun at the ones I could attend, and have been a judge at festival in NYC, so this is not sour grapes, just a heads up.
As I said, read the fine print. The two I saw (Toronto Smartphone and BetterCities) say that by SUBMITTING you give them license to do anything they want with the whole film. Worldwide. Forever. And they want you to pay them.
Yes, always read fine print. I've seen agreements like this when you enter with a special theme, like, make a commercial for Dotritos, etc. But if you see it and the film was not made for that comp, it's best to avoid it if they want to retain full rights in perpetuity.