I think you'll find it's Chapter 6 para 11.1.3
The control of an AGL system from beyond the boundary of a licensed aerodrome will only be approved by the CAA for the sole use of the emergency services. Where this type of control is desired, an operational requirement proposed by the aerodrome authority and supported by the emergency services involved should be submitted in the first instance to the CAA.
And
11.1.4
When in use, the operational status of the AGL system should be continuously monitored. An appropriate means of detecting an AGL system failure or fault and other serviceability information should be provided. The AGL system serviceability information should be provided to the AGL operator in a simple but accurate and concise way, so that if necessary the user may pass a report to flight crew. The report should enable flight crew to determine whether the AGL meets their current operational flight requirements or not (see paragraph 11.3.5).
We fell foul of this when we wanted to provide the AGL for public transport helis operating outside the published aerodrome hours.