How have courts interpreted an allegation that a defendant has served a term of imprisonment for a previous sex offence?

In People v. Franco (1970) 4 Cal.App.3d 535, 540, the court explained that, "Where an information charges the accused with a former conviction, and with having served a term of imprisonment therefor, and upon arraignment and the reading of the information to him he admits, without reservation, that he has suffered such conviction, it must be assumed that he knowingly admitted that he served the sentence as alleged in the information. To determine otherwise would be quibbling with the facts. [Citations.] Appellant's admission of the prior conviction thus included an admission that he had served a term therefor as alleged in the information, even though he was not asked, separately, whether he had served such term."