There are various formats supported for the name, mostly due to legacy concerns.
- http(s)://domain/path.ext: A fully qualified url.
- /path/from/uploads.ext: This is a locally uploaded file.
- /path/to/uploads/path.ext: A full path starting from the uploads directory (deprecated).
- ~type/path.ext: A specific type of upload provided by a plugin (deprecated).
- type://domain/path.ext: A specific type of upload provied by a plugin with additional domain information.