ISO/IEC 21000-17:2006 specifies a normative syntax for Fragment Identifiers to be used in URIs (Uniform Resource Identifiers) for addressing parts of any resource whose Internet Media Type is one of:

• audio/mpeg;
• video/mpeg;
• video/mp4;
• audio/mp4;
• application/mp4.

ISO/IEC 21000 (MPEG-21) defines an open framework for multimedia delivery and consumption, with both the content creator and content consumer as focal points. The vision for MPEG-21 is to define a multimedia framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices used by different communities.