DTG updates D-Book with accessibility and IP television guidance
October 30, 2026 08.54 Europe/London By Julian Clover


The Digital TV Group has published D-Book 12.12, updating the UK digital television receiver specification with revised guidance on controls, wireless audio and accessibility as the use of IP delivery takes hold.

The edition incorporates recommendations from an Ofcom-commissioned usability study led by the DTG, which identified difficulties experienced by older viewers using internet-delivered television.

A detailed review of receiver controls provides updated information intended to reduce confusion and accidental inputs.

D-Book 12.12 also introduces guidance on wireless audio support, covering Bluetooth Low Energy devices with or without Auracast, alongside other wideband transmission systems such as Roger. Requirements governing audio description behaviour have been clarified.

Further changes align the D-Book with HbbTV specification version 1.8.1 and set out how receivers should revert to broadcast time when internet time is unavailable.

The DTG says the proposed transition towards IP-delivered television presents a different engineering challenge from digital switchover, because services depend on multiple independently operated networks, platforms and devices.

“Broadband availability alone does not establish readiness. Capacity, coverage in the home, device compatibility, accessibility and software support all matter, alongside the performance of the service itself,” the organisation said.

It argues that agreed interfaces, clear responsibilities and coordinated testing will be needed to identify faults across the delivery chain and establish who can resolve them.

The DTG is working with members, government, Ofcom and the wider industry on a technical roadmap for the transition. Although rooted in digital terrestrial television, the D-Book continues to evolve as broadcast and IP services operate alongside one another.

The updated specification is supported by DTG Test Suites and independent testing through DTG Testing. D-Book 12.12 is available to DTG members.