>>I'm thinking he means mother's brother, father's brother, and spouse of one's aunt (though technically, that gives 4, not 3).
>
>It does, but the aunts' husbands aren't distinguished. The whole purpose of having such a detailed nomenklatura of relations was to know the hierarchical position of everybody in the extended family - which was the primary economic unit for centuries, until maybe mid-XX century. People lived in huge family cooperatives, where cooperation was actually enforced by the big boss, usually the oldest sane male :). It wasn't unusual to have four generations under the same roof.
>
>So the aunts' husbands were related to the patriarch via female members of the family, and ranked so much lower that they didn't deserve distinct names. They basically married _into_ the family, so they were pretty much outsiders.

So the distinction is only relevant where you have that kind of a hierarchy, which is presumably why you don't have the distinction in English and the Romance languages.

Tamar