For example, some states require all trustee fees to be charged equally to principal cash and income cash. If the trust document directs otherwise, however, the law allows document language to prevail. Where a document contains obnoxious, unworkable, impractical, or outdated language, the beneficiaries and trustees have recourse to local courts having general jurisdiction in equity -- most commonly for a declaration or judicial construction or for reformation of the trust to bring it into compliance with the original intent of the settlor, or to deal with circumstances not imaginable by the settlor at the time the trust was created to make the trust cy pres or as close as possible to the original intent.
When the trustee or beneficiary needs interpretation of the trust document (often but not necessarily incident to a dispute) the local probate court judge is the place to get an answer. In the trust business one speaks of "docketing" a trust, i.e. taking it to the judge. When the judge is finished, the trust is then "undocketed."