Tags are a feature on AI Dungeon used for easier navigation on the Explore page, as well as My Stuff. These are keywords that help users search and identify the content of an adventure or scenario quickly. Clicking on a tag limits to only results of that type.
Adventures And Scenarios
Tags are added in adventure settings. They can be finalized with a comma (,) or an enter/return and can have alphanumeric characters and spaces, as well as punctuation marks (other than, of course, commas). When a scenario has tags, you can search for that tag with the search bar in My Stuff to find things with that tag easier.
If you publish your adventure/scenario, the tags you add to it will be visible to everyone. Users can search this tag in Explore to find adventures and/or scenarios with that tag.
The #nsfw tag is used to designate NSFW (not safe for work) adventures/scenarios. This tag must be added in order for the AI to generate NSFW outputs.
The #scripted tag can be used to show off scripting scenarios. This tag was included in the announce of scripting to make it easier for people to share scripted scenarios.