tag 17 linkage string
tag 18 linkageType string
tag 19 recordSource string
-tag 20 controlledTerm string
+tag 20 controlledTerm/ct string
tag 21 thesaurus string
-tag 22 localSubjectTerm string
+tag 22 localSubjectTerm/lst string
tag 23 originalControlIdentifier string
tag 51 purpose structured
tag 95 controlledVocabulary structured
tag 96 indexTermsControlled structured
tag 97 localSubjectIndex structured
-tag 98 crossReference structured
+tag 98 crossReference/cr structured