Closed
Description
The Variant Key Mismatch errors are miscategorized in Variant Key Mismatch errors as being "Data Model errors". They are clearly syntax errors, and do not require any knowledge of the data model or "semantics" to detect. Instead, they are syntactic errors, and can be detected in parsing.
I think there is a bit of confusion because they are not detectible by the BNF. But that should not be the criterion. There are many instances in many specifications of syntax errors that are not detectible by a BNF processor, such as Well-formedness constraint in https://www.w3.org/TR/xml/#sec-logical-struct and elsewhere.