Reddit glossary
What is AutoModerator on Reddit?
AutoModerator is a bot that mods set up to remove or flag posts that match certain rules, like a missing flair or too little karma.
It runs on rules written by each community's mods. It can hold a post for review, remove it, or reply with a message.
Most surprise removals for new accounts come from AutoModerator, not from a person. Common triggers are account age, karma, banned words and links to certain sites.
If you are promoting something
If your post vanishes right after you submit it, an automatic rule is the most likely cause. Message the mods and ask what the rule is.