Added an explanation about the cache.

paths/qoc_indicator_{setKey}_{indicatorKey}_participants.yaml

@@ -3,7 +3,7 @@ get:
   tags:
     - Quality of Care
   summary: Indicator, practice details
-  description: Show per-practice details for each practice in a group for a specific indicator
+  description: Show per-practice details for each practice in a group for a specific indicator.
   parameters:
     - name: setKey
       in: path

schemas/IndicatorParticipants.yaml

@@ -91,6 +91,11 @@ properties:
         - amplitude
         - population
         - values
+  cache:
+    type: boolean
+    description: |- 
+      If true, the indicator was retrieved from the API cache. The indicator is only retrieved from the cache if there is no recent calculation available in the database and if the indicator won't change anymore. This is the case when it was calculated with a reference date in the past and for which a certain period no new HIS-data is provided. The cached indicator reflects the indicator definition on the reference date. A cached indicator is not updated when the definition changes.
+    example: true
 required:
   - group
   - key