As described in that post:
https://forums.autodesk.com/t5/inventor-nastran-forum/composite-material-use-of-a-global-ply-identif...
The idea would be to use the Global Ply ID number to facilitate the post processing of complex laminates:
![2020-10-15_17-40-41.jpg 2020-10-15_17-40-41.jpg](https://forums.autodesk.com/t5/image/serverpage/image-id/831844i26ACCFE085938111/image-size/large?v=v2&px=999)
NASTRAN can store the Global Ply number, but Inventor cannot use it.
Pierre