Prvalue

Together, prvalues and xvalues are called “rvalues,” reflecting the use of that term in the library clauses and the intended uses in reference binding, overload resolution, and template argument deduction.

Source: wiktionary

In Pittsburgh (and a few places later), I had the opportunity to explain this terminology to several people. It can be done in a few minutes. I think it has prvalue (Groan!).

Source: wiktionary

If the expression is categorized as an rvalue, the next evaluation can categorize it as a prvalue or xvalue.

Source: wiktionary