GIFs

Are gif avatars and signatures allowed?

Curious because of the strob light that some players could use, because some people are light-sensitive and in worst cases it may cause them epilepsy (many games and forums have policies against gif/strob light)
For example, for me personally strob light is a mild problem, so is there any option to turn off avatars and signatures (of other players)?

There are some players who use same flashy gif in a row in signature, which cause problems to read forum.