Oof. They will normally give you a reason, or you can ask the mods. Though reddit wide has this rule about: Rule 4 – No Self-Promotion (links to your own project are OK only if you already have a history of regular, non-promotional participation) It's a bit of a silly rule, and not consistently applied. I dont do it on r nostr at all. But very often in a large sub they'll remove something for that.