A receiver for receiving at least one Electronic Service Guide fragment, the receiver comprising an input, a processor and a memory, the receiver being configured to perform: storing at least one descriptor of at least one previously received ESG fragment; and receiving a list of descriptors including at least one descriptor corresponding to at least one ESG fragment wherein the received at least one descriptor includes topology information specifying content of the one ESG fragment, wherein the list of descriptors is received on an announcement channel and wherein the list of descriptors includes an identifier descriptor and a version descriptor corresponding to at least one ESG fragment and the at least one descriptor stored in memory includes at least one identifier descriptor and a corresponding version descriptor corresponding to a stored ESG fragment; comparing the received at least one descriptor with the stored at least one descriptor, determining that an ESG fragment corresponding to the received at least one descriptor is not to be received if the received at least one descriptor matches the stored at least one descriptor; determining that an ESG fragment, in a delivery channel corresponding to the received at least one descriptor is to be received from the delivery channel if the received at least one descriptor does not match the stored at least one descriptor; storing an ESG fragment determined as an ESG fragment to be received and corresponding descriptors in the memory; determining whether the identifier descriptor and the version descriptor corresponding to the received ESG fragment matches an identifier descriptor and a corresponding version descriptor in the memory; and determining that the identifier descriptor of the received ESG fragment matches the identifier descriptor in the memory and the version descriptor corresponding to the identifier descriptor of the received ESG fragment is greater than the version descriptor corresponding to the identifier descriptor in the memory and determining that the ESG fragment corresponding to the identifier descriptor and corresponding version descriptor in the memory is to be deleted. storing at least one descriptor of at least one previously received ESG fragment; and receiving a list of descriptors including at least one descriptor corresponding to at least one ESG fragment wherein the received at least one descriptor includes topology information specifying content of the one ESG fragment, wherein the list of descriptors is received on an announcement channel and wherein the list of descriptors includes an identifier descriptor and a version descriptor corresponding to at least one ESG fragment and the at least one descriptor stored in memory includes at least one identifier descriptor and a corresponding version descriptor corresponding to a stored ESG fragment; comparing the received at least one descriptor with the stored at least one descriptor, determining that an ESG fragment corresponding to the received at least one descriptor is not to be received if the received at least one descriptor matches the stored at least one descriptor; determining that an ESG fragment, in a delivery channel corresponding to the received at least one descriptor is to be received from the delivery channel if the received at least one descriptor does not match the stored at least one descriptor; storing an ESG fragment determined as an ESG fragment to be received and corresponding descriptors in the memory; determining whether the identifier descriptor and the version descriptor corresponding to the received ESG fragment matches an identifier descriptor and a corresponding version descriptor in the memory; and determining that the identifier descriptor of the received ESG fragment matches the identifier descriptor in the memory and the version descriptor corresponding to the identifier descriptor of the received ESG fragment is greater than the version descriptor corresponding to the identifier descriptor in the memory and determining that the ESG fragment corresponding to the identifier descriptor and corresponding version descriptor in the memory is to be deleted.