Xanathar's 18 Pages of What??

[TheCosmicKid]

In this context, I am assume you misspoke and meant praenomen. As the cognomen doesnt become the personal name until the empire.

What briggart said is entirely correct for cognomina and would be incorrect for praenomina. So I would asssume that they said what they meant.

Also, the term ‘family name’ is misleading because in modern English, it means the sir name, the clan name. The nomen is the clan name.

There is a difference between a family and a clan, and the modern English family name is not a clan name. Can you please acknowledge that this is the point I have been trying to make to you from the beginning, even if you disagree with it? It would make you look a little less like you're begging the question.

Also: "surname". Nothing to do with "sir".

It implies that everyone in the ‘family’ has this name, when this would be incorrect.

Everyone in the family for whom it is possible to have the name (i.e.: the boys) has the name.

It implies that it is a formal or even legal term, when it was informal and inconsistent.

Why on earth should a family name have to be formal and consistent to be a family name? (Never mind that the use of the cognomen as a family name was pretty formal and consistent by the era of Caesar, Crassus, Brutus, Cicero, and Cato... whose names were all examples of this.) If a certain name is used to identify a family, it makes sense to call it a "family name", even if it's not a legal term and/or not every family in the culture has one. What else would you call it?

I am glad you called out Caesar as ‘atypical’. Because while giving a child a fathers name is common, it is also common giving a child the mothers name.

On the contrary, it was quite rare. And has nothing to do with the reason Caesar's name became atypical, so I don't understand what you're trying to say by bringing it up.