$B$ is complete $\iff$ every member of $B$ is a subset of $B$; is there another term for 'complete'?

Question

I'm reading Suppes' Axiomatic Set Theory, and this definition is on page 130 when we begin building the ordinal numbers. I can't seem to find any reference on either MathSE or google about complete sets in specifically this sense. Is there another term for it? It likely seems related to order, but I can't seem to find any explicit connection.