Merge pull request #26 from linkml/linkml-issue-177

Adding recommended field

model/schema/meta.yaml

@@ -607,6 +607,17 @@ slots:
     inherited: true
     description: true means that the slot must be present in the loaded definition
 
+  recommended:
+    domain: slot_definition
+    range: boolean
+    inherited: true
+    description: true means that the slot should be present in the loaded definition, but this is not required
+    comments:
+      - This is to be used where not all data is expected to conform to having a required field
+      - If a slot is recommended, and it is not populated, applications must not treat this as an error. Applications may use this to inform the user of missing data
+    see_also:
+      - https://github.com/linkml/linkml/issues/177
+
   inlined:
     domain: slot_definition
     range: boolean
@@ -1031,6 +1042,7 @@ classes:
       - readonly
       - ifabsent
       - required
+      - recommended
       - inlined
       - inlined_as_list
       - key