Betareaders Fanfiction

If you are a beta you are proof-reading other people's work instead of writing your own (though of course you can be a normal writer as well). The beta profile tells authors what type of work you would be happy to beta and what stuff you don't want to read, ie, you can say you are okay proof-reading scenes of violence (like battle scenes) but not okay with scenes of non-con or child abuse, ect.