set
Assign a name to the specified object type. If the only field key A_Atoms in the object type are special atoms, then the name will not be recorded (unless allowSpecialAtomsToHoldName is true, which is really only for naming special object types like Exceptions.exceptionType). Note that it is technically legal for there to be multiple names for a particular object type, although this is of questionable value.
Parameters
an
An object type.
a
A name.
allow
Whether to allow the object type name to be attached to a special atom.