In the draft expression, you can substitute each column reference with a more detailed expression to return just the abbreviation that you want. For example:
It’s generally possible to represent all your required logic in an AppSheet expression that generates an identification code. However, beware designing dependencies on serial numbers. You may be better off assigning each item a randomly generated UNIQUEID in one column and a logic-based SKU in another column. That’s especially the case if you need duplicate SKUs (e.g., “can I also have same sku generated”).
Schaue doch mal dieses kurze Erklärvideo an, wie man automatisch fortlaufende Nummern zur einer Kategorie erhält. In Kategorien fortlaufende Nummern generieren . Wäre auch eine Lösungsansatz zur Erstellung eines neuen Artikels.