Is this a valid layer - NCS/AIA 3.1

[madcadder]

I'm trying to figure out how to write a layer valid to NCS/AIA 3.1:

Version 2.0 allows: "S-METL-MISC" for misc. structural metals.
Version 3.1 allows: "S-XXXX-METL for "Any major group: misc metals.

There is only one reference to "METL" in each standard and that is in the "S"tructural Discipline Designator.

I am trying to make a "Z" Discipline Designator (for Contractor/Shop Drawings) with a "METL" Major Group, "ELEV" as the Minor Group, and "PATT" as the Second Minor Group. No Status Field needed.

Does that work to NCS/AIA 3.1 if written: "Z-METL-ELEV-PATT"?
or
do I have to leave the "METL" as a Minor Group since that is where it is originally defined in the Structural Discipline Designator in NCS 3.1 and write it as "Z-ELEV-METL-PATT"?
or
being that "O" and "Z" have no predefined Major or Minor Groups, per 2.0 or 3.1, am I free to put all this in any way I want? Within reason...

Logic behind all this is:
The contractor, "Z", who is providing all the misc "METL" for the job has drawn an "ELEV" that uses a hatch "PATT"ern. Bingo! Easy!

or is it...

[cadtag]

Z-ELEV-METL-PATT

Discipline = Z since the discipline is Contractor/Shop Drawing, then ELEV as the Major Group Code since it's a "Drawing View" layer

then METL and PATT as minor groups.