Merge pull request #354 from FHIR/content-type-binding-extensible

Make SQLQuery contentType binding extensible

Author: johngrimes

input/fsh/profiles/library-profiles.fsh

@@ -26,7 +26,10 @@ versioning.
 * content 1..* MS
 * content.contentType 1..1 MS
 * content.contentType ^short = "application/sql or application/sql;dialect=..."
-* content.contentType from AllSQLContentTypeCodes (required)
+* content.contentType from http://hl7.org/fhir/ValueSet/mimetypes (required)
+* content.contentType ^binding.additional[+].purpose = #extensible
+* content.contentType ^binding.additional[=].valueSet = Canonical(AllSQLContentTypeCodes)
+* content.contentType ^binding.additional[=].documentation = "SQLQuery content types, including dialect-specific variants. Authors SHOULD use a code from this value set when one applies; codes outside this value set MAY be used for SQL dialects not yet enumerated, subject to the sql-must-be-sql-expressions invariant."
 * content.extension contains sql-text named sqlText 0..1 MS
 * content.extension[sqlText] ^short = "Plain-text SQL for readability"
 * content.data 1..1 MS

input/pagecontent/StructureDefinition-SQLQuery-intro.md

@@ -108,8 +108,11 @@ same logical result set.
 
 ### Conformance
 
-**Terminology:** `contentType` SHALL come from
-[All SQL Content Type Codes](ValueSet-AllSQLContentTypeCodes.html).
+**Terminology:** `contentType` SHOULD come from
+[All SQL Content Type Codes](ValueSet-AllSQLContentTypeCodes.html). The binding
+is extensible: when one of these codes covers the dialect, that code SHALL be
+used; otherwise, an alternative code MAY be supplied (subject to the constraint
+that every `contentType` starts with `application/sql`).
 
 **Constraints:**