string
The class of ident, its value will depend on what ident is. For an object of a user-defined structure, the class is the full name of the structure, e.g. ~test.stool
For an identifier object of a system type, the class is the type name, e.g. numeric, window etc.
For a type identifier (e.g. string), the class is command.
This element is maintained by the system and cannot be changed.