No need to introduce the confusing "model" here. See also parid0294, parid0398, parid0399, parid0423, parid0970, parid0971, parid0989, parid2014, parid2226. REF: parid0402 TXT: A list of syntactic constructs ("node demanders") whose instances can be unambiguously addressed within the instances of the syntax must be provided. FIX: The Syntax Processing Procedures must provide a list of syntactic constructs ("node demanders") whose instances can be unambiguously addressed within the instances of the syntax must be provided.