[GAIUS libro septimo decimo ad edictum prouinciale. ] §28.2.30.prInter cetera, quae ad ordinanda testamenta necessario desiderantur, principale ius est de liberis heredibus instituendis uel exheredandis, ne praeteritis istis rumpatur testamentum: namque filio qui in potestate est praeterito inutile est testamentum.
Among other things which are of necessity required for drawing up wills, the primary rule concerns appointing children as heirs or disinheriting them, lest by passing them over the will be broken: for if a son who is in power is passed over, the will is of no effect.