The GIL is not a required language feature. Neither Jython nor IronPython have a GIL. What would it mean to have a language standard? A publication from ISO or

The GIL is not a required language feature. Neither Jython nor IronPython have a GIL. What would it mean to have a language standard? A publication from ISO or ECMA? I ask because the Python Language Reference at https://docs.python.org/3/reference/index.html https://docs.python.org/3/reference/index.html seems to be a (terse) language standard. Among other things, it highlights some of the things which are implementation defined, rather than language defined.