Originally Posted by
Lomapaseo
As a related question
How does Delta decide at the lounge what membership level you have?
My understanding is that when you scan your barcode, it brings up your name, status and SC membership level.
The first time I used it as a DM, all I had with me was a boarding pass and they let me in.
Since my account has been updated, I now have a SC 'card' on my phone that I use to scan in.
So I believe that any identifier, whether Medallion card, boarding pass or club card will have 'linked knowledge' of the membership level.