Subreddit

Reddit is a stack of separate communities and each one is a subreddit, written with the r slash prefix. Every sub sets its own rules and enforces them without appeal to anything outside itself. Building one around a channel works only once there is an audience with something to say to each other. Taking part in existing subs works far sooner, and comes with a hard requirement: read the self-promotion rule first, because a link dropped into a community you have never contributed to gets removed within minutes.