The Trust Policy node in the Active Directory Federation Services snap-in represents the trust policy configuration information that is stored in the trust policy file. The trust policy file is stored in an .xml file format. It is created during setup of the first federation server in the federation server farm. The trust policy file path is configured in the local Web.config file. When possible, store the trust policy file on a network share so that it can be accessed by all the computers in the federation server farm.
We strongly recommend that you use the Trust Policy node to edit trust policy configuration information. You cannot edit the trust policy configuration information in the file manually.