of the main character(s) in your doc, which are nice for you to secure
in writing in case someone wants to make a fiction film based on their
lives after seeing the documentary.
Not always easy to get. It brings up possible issues of the subjects
feeling exploited, so you should tread carefully and find out from an
entertainment lawyer how to go about it. Also, wouldn't do it unless
you feel your character and his or her situation is so compelling that
Hollywood is sure to come calling.