2.1.2.163 S274, Multisets of reference types

V0199:

The specification states the following:

 Subclause 6.1, "<data type>":
  
 <data type> ::=
 <predefined type>
 | <row type>
 | <path-resolved user-defined type name>
 | <reference type>
 | <collection type>
  
 ...
  
 <reference type> ::=
 REF <left paren> <referenced type> <right paren> [ <scope clause> ]
  
 ...
  
 <collection type> ::=
 <array type>
 | <multiset type>
  
 ...
  
 <multiset type> ::=
 <data type> MULTISET
  
 ...
  
 Conformance Rules
  
 Without Feature S274, "Multisets of reference types", conforming SQL language shall not contain a <multiset type> that is based on a <data type> that contains a <reference type>.

Microsoft SQL Server 2008 R2 and Microsoft SQL Server 2012 vary as follows:

Transact-SQL does not support this feature.