[dty01]
Every div type reference must be valid in every source
Affects: @div-type-ref<div-type-ref> <equate-div-types> <rename-div-ns> <suppress-div-types>
@div-type-ref
<div-type-ref>
<equate-div-types>
<rename-div-ns>
<suppress-div-types>
Used by template ŧ prep-class-2-doc-pass-2
ŧ prep-class-2-doc-pass-2
Used by function tan:group-by-IRIs()
tan:group-by-IRIs