CharacteristicSpecfication (for both YAML and JSON) schema is incorrect.
It says the following for YAML (4.3.7):
String: String *
and the following for JSON (5.13):
It is not clear why there is an attribute name called 'String'. A JSON attribute name must be unique therefore the cardinality of "*" is not possible. It is also not clear why the value must be a 'String' (and not something like Number)