#287: Clarified allowable data types for context fields that can be used as prefetch tokens.

Author: brynrhodes

docs/specification/1.0.md

@@ -690,7 +690,7 @@ Often a prefetch template builds on the contextual data associated with the hook
 
 The token name would be `{{context.patientId}}`. Again using our above conditions example, the complete prefetch template would be `Condition?patient={{context.patientId}}`.
 
-Only the first level fields in context may be considered for tokens. Hook creators MUST document which fields in the context are supported as tokens. If a context field can be tokenized, the value of the context field MUST be a data type that can placed into a FHIR query (eg, string, number, etc).
+Only the first level fields in context may be considered for tokens. Hook creators MUST document which fields in the context are supported as tokens. If a context field can be tokenized, the value of the context field MUST be a JSON primitive data type that can placed into a FHIR query (i.e. a string, a number, or a boolean).
 
 For example, given the following context that contains amongst other things, a Patient FHIR resource: