As a new user, I’m working through the whole ‘category’ issue as well. Migrate from sickbeard
Connecting Sickbeard to Sab requires no categories to be set in Sab. But from replies I’ve gotten in the above link, it seems that Sonarr does require categories to be setup in Sab. I’m still a bit unclear why and what the purpose of categories are in the first place. I’ve never needed them before with sick/sab.