At least one computing device-readable storage medium comprising instructions stored thereon wherein the instructions, in response to execution by a computing device, cause the computing device to: form a multicast data unit with multiple portions of data (406, 410), each portion of data corresponding to one of multiple content items (206, 208) to be transmitted to multiple receiving devices by the computing device, each content item to be displayed by one or more of the multiple receiving devices, wherein the content items include a first content item and a second content item that is different than, and independent from the first content item, wherein the first content item is to be displayed by a first receiving device of the multiple receiving devices using at least a first portion of data that corresponds to the first content item, wherein the second content item is to be displayed by a second receiving device of the multiple receiving devices using at least a second portion of data that corresponds to the second content item, characterised in that to form a multicast data unit comprises to include in the multicast data unit the first portion of data, the second portion of data, an identifier associated with the first receiving device, an identifier associated with the second receiving device and a data portion offset associated with the identifier associated with the first receiving device and a data portion offset associated with the identifier associated with the second receiving device, wherein the data portion offset associated with the identifier associated with the first receiving device describes where the first portion of data is found in the multicast data, the data portion offset associated with the identifier associated with the second receiving device describes where the second portion of data is found in the multicast data; and transmit the formed multicast data unit to the multiple receiving devices, whereby each receiving device is enabled to retrieve from the multicast data unit a portion of data that corresponds to a content item to be displayed by the receiving device based on the identifier associated with the receiving device and included in the multicast data unit and based on the data portion offset associated with the identifier, and to display the content item. form a multicast data unit with multiple portions of data (406, 410), each portion of data corresponding to one of multiple content items (206, 208) to be transmitted to multiple receiving devices by the computing device, each content item to be displayed by one or more of the multiple receiving devices, wherein the content items include a first content item and a second content item that is different than, and independent from the first content item, wherein the first content item is to be displayed by a first receiving device of the multiple receiving devices using at least a first portion of data that corresponds to the first content item, wherein the second content item is to be displayed by a second receiving device of the multiple receiving devices using at least a second portion of data that corresponds to the second content item, characterised in that to form a multicast data unit comprises to include in the multicast data unit the first portion of data, the second portion of data, an identifier associated with the first receiving device, an identifier associated with the second receiving device and a data portion offset associated with the identifier associated with the first receiving device and a data portion offset associated with the identifier associated with the second receiving device, wherein the data portion offset associated with the identifier associated with the first receiving device describes where the first portion of data is found in the multicast data, the data portion offset associated with the identifier associated with the second receiving device describes where the second portion of data is found in the multicast data; and transmit the formed multicast data unit to the multiple receiving devices, whereby each receiving device is enabled to retrieve from the multicast data unit a portion of data that corresponds to a content item to be displayed by the receiving device based on the identifier associated with the receiving device and included in the multicast data unit and based on the data portion offset associated with the identifier, and to display the content item.