The Trill Evaluation Board was an organized body of administrators on Trill and a branch of the Symbiosis Commission. The Board was responsible for evaluating Trill who were candidates to join with a symbiont and for preparing them for life after joining.
In 2375, Ezri Dax met with the Trill Evaluation Board several times after undergoing an emergency joining with the Dax symbiont. Unfortunately, beyond giving her counseling and some books to read, there was little they could do for her since she and the symbiont were already joined. (DS9: "Shadows and Symbols")