The mere deciphering of ancient, handwritten documents is an art in itself. And here again it is not unusual to encounter conflicting evidence in the shape of documents that purport to describe the same property but that describe it differently. Or you may find a document in which some of the languages may bear more than one interpretation. In this last case you apply, as well as you can, a legal maxim to the effect that an ambiguous document should be given the sense that the maker of the document may be reasonably presumed to have intended. The determination, after study of all the documents and related evidence, of what the true property description may be presumed to be, and from this a determination of what physical evidence of the boundary location exists in the field.
Physical evidence means for the most part monuments.
In land-surveying speech, a monument is any identifiable object that occupies a permanent location in the field and serves as a reference point or marker for a boundary. Do not use perishable markers for monuments, such as a wooden marker that decays easily. The location, in the field, of the existing physical evidence of the boundaries. The establishment of the boundary. That involves those decisions previously mentioned as to the best evidence.