http://hl7.org/fhir/StructureDefinition/contactpoint-local|5.2.0

The local number that must be dialed to connect within the area/city/zone. This extension is used when a system wishes to designate specific parts of a phone number (and potentially place constraints on which components must be present and how they're filled in).
NameFlagsCardTypeDescription & Constraints
Extension
0..1Local number that must always be dialled
 
extension
?..0
 
url
?..?
 
value[x] *
1..?
 
 
valueString *
1..?string