o  The tag value clause specifies a value or set of values  for  the
      tag variable in each VARIANT of a VARIANTS field collection.  The
      tag variable can then be used at run time  to  find  the  current
      VARIANT.

   o  Languages that do not support tag variables ignore the tag  value
      clause.   For  more information on language support of CDD record
      definitions, refer to the documentation for the language you  are
      using.

   o  Each variant begins on the same byte in the  record,  subject  to
      individual  alignment options.  The length of the longest VARIANT
      in the collection determines the overall length of  the  VARIANTS
      field description.

   o  Be sure that the VARIANT collection you define  conforms  to  the
      requirements  of  the  language  or  language processor that will
      access the record definition.

   o  VAX DATATRIEVE requires each VARIANT to contain a STRUCTURE field
      description statement at the top of the VARIANT.