Part 3: Communications Data etc Communications data Section 13: Meaning of "communications data": subscriber details
This section makes clear "communications data" includes entity data that comprises the content of a communication made for the purpose of initiating or maintaining an entity’s access to a telecommunications service. It is also the content about an entity to which that telecommunications service is provided or will be provided. It is not the data comprised in the recording of speech, for example voicemails. This will have the practical effect of clarifying that this data is communications data rather than content.