This code system https://fhir.nhs.uk/CodeSystem/Ambulance-ExistingTreatmentPlans defines the following codes:

CodeDisplay
01No Treatment Plan in Place - SOP applied
02EOL
03DNACPR
04Advanced Care Plan / Directive
05Rare condition
06Mental Health
07Learning disability
08Social Care
09Long term condition
10Hospital at home
11Direct ward / specialist unit access
12Emergency Treatment Plan
13Other Treatment / Care Plan