Being a member of the UBF means that you pledge that your board is supportive of free speech and other people's comments and opinions.
Being a member of the UBF is a promise that your board is free from "rulecuckery".
When you partner with the UBF, the UBF partners with you; if you want a link to your board on >>>/ubf/, you have to put a link back. In this way all UBF boards are linked, increasing traffic and bringing new people to boards they only dreamed about never knew about before.