Meta tags are tags that convey information about an image outside of what is visible in it. For the search syntax feature of the same name, see Help:Cheatsheet.
The basic rule of thumb is that a meta tag describes what a post is, while general tags describe what a post contains. This has some exceptions, such as JPEG Artifacts or Scan Artifacts.
Examples of things meta tags are used for:
- Image resolution (Lowres, Highres)
- Post medium (Animated, Photo (Medium))
- Edits (Third-Party Edit, Stitched)
- Source information (Non-Web Source, Third-Party Source)
- Tagging information (Tagme, Character Request)
- Post origin (Commission, Fan Request)
For a list of meta tags, see Tag Group:Metatags.