Many rules of customary law have crystallised to such an extent (through repeated acknowledgment by the Royal Court and in the way people conduct their affairs) that everyone accepts them as binding without discussion. The boundaries of the parishes, the existence of the office of Bailiff, and various rules relating to possession of land and inheritance fall into this category. Many rules of customary law are to be found discussed in the texts of the 'commentators' and the case law of the Jersey courts. Where the works of the commentators do not deal with situation, the Jersey courts look at factual evidence to work out is the "generally accepted usage and practice".See e.g. [2007] JRC 151
