The Digital TV Group publishes and maintains the UK technical specification for high-definition services on digital terrestrial television (Freeview) based on the new DVB-T2 standard. The specification is known as the D-book. Freeview HD is the first operational TV service in the world using the DVB-T2 standard. This standard is incompatible with DVB-T, and can only be received using compatible reception equipment. Some television receivers sold before the HD launch claimed to be "HD-ready", but this usually implies that the screen can display HD, rather than that DVB-T2 signals can be received a suitable tuner (typically built into a STB or PVR) is additionally required. Freeview HD set-top boxes and televisions are available. To qualify for the Freeview HD logo, receivers will need to be IPTV-capable and display Freeview branding, including the logo, on the electronic programme guide screen. The Freeview HD trademark requirements state that any manufacturer applying for the Freeview HD logo should submit their product to the Digital TV Group's test centre (DTG Testing) for conformance testing.