Quote Originally Posted by MacMillan of Rathdown View Post
To further the land ownership analogy, the difference between arms held by prescriptive right and those held by substantive right could be likened to "squatters" rights, vs. deeded rights
But there is no difference. Ownership of land by prescription is every bit as valid as ownership by grant or deed. Moreover, prescriptive rights are even stronger under the civil law (of which the law of arms is considered to be a part) than under the common law governing land ownership. Here are the words of the English civil law expert Wolsely Emerton, DCL, from a 1904 article entitled "The Armiger" by the eminent Canadian heraldic scholar Marion Chadwick:

That rights are established by user is, in the Civil Law, a rule so notorious that the only difficulty is to choose one’s authorities; and it must be noted that (contrary to the general principle of English statutes of limitation) the Civil Law does not only “bar the remedy of an opponent,” but actually “confers a right” on the originally wrongful possessor. [Emerton then provides specific citations to the Institutes and Pandects, two of the classic sources of Civil Law.] Looking on the right to arms from the civilian’s [i.e., civil law specialist's] point of view, an unchallenged possession of twenty years at most would be sufficient as a rule.

It is important that the possession should have begun in good faith (which is, of course, presumed unless the contrary be proved), but it is not necessary that the good faith should continue till the time of “prescription” has expired.
Chadwick's full article can be seen at http://mysite.verizon.net/vzeohzt4/d...k-Armiger1.pdf.