SKU Format DISC123546N1
A Magento product is created with the SKU in the format of DISC[release id]N[x]
For example DISC17518N1 is the sku for 'Jeff Mills – Waveform Transmission Vol. 1' - https://www.discogs.com/release/17518
If you have 10 listed that are exactly the same the system will add a qty of 10 to this product
For each new variation of price, condition, comments, location etc a new product is created with the suffix adjusted so DISC17518N2, DISC17518N3 and so on.
So for example, you might have
DISC17518N1 VG+/VG+ 3.99
DISC17518N2 VG+/VG+ 3.49
DISC17518N3 M/NM 10.99
DISC17518N4 M/NM 9.99 'Sticker on cover'
Discogs inventory is imported into D2MPro > Discogs Imports > Inventory
Listings are allocated to an SKU.