Fragment identifier

When a URI reference is used to perform a retrieval action on the identified resource, the optional fragment identifier, separated from the URI by a crosshatch ("#") character, consists of additional reference information to be interpreted by the user agent after the retrieval action has been successfully completed. As such, it is not part of a URI, but is often used in conjunction with a URI.

fragment     = *uric

The semantics of a fragment identifier is a property of the data resulting from a retrieval action, regardless of the type of URI used in the reference. Therefore, the format and interpretation of fragment identifiers is dependent on the media type [RFC2046] of the retrieval result. (cf. Uniform Resource Identifiers (URI): Generic Syntax)

The fragment-id follows the URL of the whole object from which it is separated by a hash sign (#). If the fragment-id is void, the hash sign may be omitted: A void fragment-id with or without the hash sign means that the URL refers to the whole object. (cf. Universal Resource Identifiers in WWW)

Resources

 * Is a fragment ID a URI reference?
 * URI References: Fragment Identifiers on URIs