Enum's always get moved up to the package level and as such always get added to the Global This create two different ways it can get handled, but we only have one code path for both! 1) When the enum is embedded within the Properties it will need to return a Reference as the enum will be moved up to the global level and the parent struct will need this reference field to the enum 2) When the enum is within the Definitions a field reference is not required, as any reference to it would come from a $Ref, as such no Reference is required on the return, the returned reference will get ignored in the calling code of HandleStruct, because it will try and add the returned Reference to the global level but as it's name/key will match on the already added Enum name/key bellow it will get ignored.