As in they have numerous neck profiles they were shaped to for a number of years which are on the G&L website looking at depth, radius, shape etc. Modern C, classic etc.
For example the #12 neck is very much their PJ so between the 2.
#8 is super skinny profile, #6 (I think, could be 7) was very wide like about 44mm but flat and hence was fat.
I have lost touch, and they may have stopped that as much now, but there was certainly some variation for a time depending on what someone ordered, and they seemed to go with a #12 as a default for a period, as I say I may be out of touch.
It may well say in the case candy.
cheers