Derogatory Clause

In a will, this is a sentence or secret character inserted by the testator, of which he reserves the knowledge to himself, with a condition that no will he may make thereafter should be valid, unless this clause be inserted word for word, This is done asa precaution to guard against later wills being extorted by violence, or otherwise improperly obtained. By the law of England such clause would be void, as tending to make the will irrevocable.

Wharton.

Derogatur legi, cum pars detrahitur; abrogatur legi, cum prorsus tollitur. To derogate from a law is to lake away part of it; to abrogate a Jaw is to abolish it entirely.

Dig. 50, 17, 102.