• When CodeList describes an integer or floating point number and Atomic is a variable, Atomic will be unified with the numeric value described by CodeList (e.g., name(N, "300"), 400 is N + 100 succeeds).
• If CodeList is not a representation of a number, Atomic will be unified with the atom with the name given by the character code list.
• If Atomic is an atom or number, the unquoted print representation of it as a character code list is unified with CodeList.

This predicate is part of the Edinburgh tradition. It should be considered deprecated although, given its long tradition, it is unlikely to be removed from the system. It still has some value for converting input to a number or an atom (depending on the syntax). New code should consider the ISO predicates atom_codes/2, number_codes/2 or the SWI-Prolog predicate atom_number/2.