Help: Tags
Tags are basically keywords you can use to describe posts, allowing you to easily search and explore posts based on their content. Consult the cheat sheet for a full list of what you can search on.
Guidelines
When you're tagging a post, use the following guidelines:
Replace spaces with underscores
For example, looking at viewer becomes looking_at_viewer. This small concession makes other features much easier to implement.
Forbidden characters
Commas and semicolons are illegal characters and are stripped from tags.
Artist Names
When adding a new artist tag, attempt to use an alias instead of the artist's real name. If they go by their real name with everything else, then use their real name.
Ask
If you're not sure whether a tag is right or wrong, then post a forum topic asking for some opinions. There are plenty of obsessive e621 fans who will gladly weigh in.
Types
Tags can have a type. Currently there are only four types: artist, character, copyright, and general.
Artist
Artist tags identify the tag as the artist. This doesn't mean the artist of the original copyrighted artwork (for example, you wouldn't use the ken_sugimori tag on a picture of Pikachu drawn by mellis).
When tagging something, you can tell e621 that a tag is an artist tag by prefixing it with artist:. For example, tagging something artist:mark tree will tag a post with mark and tree. If the mark tag doesn't already exist, it'll be created with the tag type set to artist.
Character
Character tags identify the tag as a character. They work exactly like artist tags, only you prefix with "character:" (or "char:").
Copyright
The copyright type indicates the tag represents a game, a novel, an anime, or some sort of copyrighted setting. Otherwise they work identically to character and artist tags, only you prefix with "copyright:" instead (or "copy:").
General
General tags are tags that have no other type. This includes common tags like nude, male, and monochrome. Set a tag as a general tag by prefixing it with general:
Meta tags
rating:s/q/e
Sets the rating of the post. Can either be s (or safe), q (or questionable), or e (or explicit).
pool:123
Submits the post to the given pool (in this case, the pool with the id 123).
-pool:123
Removes the post from the given pool (in this case, the pool with the id 123).
parent:123
Sets the current post's parent to the post with the given id (in this case, post #123).
child:123
Sets the given post to a child of the current post (in this case, it will set this post as a parent of post #123). This is useful when uploading an updated version of an existing post; just add child:{id of original post} to the new post and it will set it as the parent of the original post.