9. A method implemented by a provider in a broadcasting system for managing metadata for multimedia program content scheduled for broadcast in the broadcasting system, the method comprising: receiving by the provider from a client device in the broadcasting system a request for updating a lower fragment containing metadata related to the scheduled multimedia program content, the client device storing the lower fragment in a previously received electronic document, wherein the electronic document has a hierarchical structure based on a prescribed syntax and the hierarchical structure includes an upper fragment located above the lower fragment which is identified by a fragment identification; and in response to the request, sending from the provider to the client device an update document having a structure based on the prescribed syntax, the update document including the upper fragment and an invalid element, wherein the invalid element specifies that information in the lower fragment is invalid.
9. A method implemented by a provider in a broadcasting system for managing metadata for multimedia program content scheduled for broadcast in the broadcasting system, the method comprising: receiving by the provider from a client device in the broadcasting system a request for updating a lower fragment containing metadata related to the scheduled multimedia program content, the client device storing the lower fragment in a previously received electronic document, wherein the electronic document has a hierarchical structure based on a prescribed syntax and the hierarchical structure includes an upper fragment located above the lower fragment which is identified by a fragment identification; and in response to the request, sending from the provider to the client device an update document having a structure based on the prescribed syntax, the update document including the upper fragment and an invalid element, wherein the invalid element specifies that information in the lower fragment is invalid. 11. The method of claim 9 wherein the invalid element specifies the fragment identification.