batninth
If you do a route brief or Aerodrome brief that included Church Fenton, you would find it in Nav Warnings as well as in the FIR Brief.
Ensuring that you include aerodromes along your intended route as well as departure and destination will help cut out a lot of the chaff that you may not need to trawl through.
All briefing systems require some time spent with them to find the functions that suit you best. If the HELP tab on the NATS AIS website is baffling to you, then give them a ring and they will guide you through the most appropriate briefing function for your requrements.