The Epub Structural Semantics Vocabuarly has undergone revision after the 1.0 release. The current ESSV version 1.1 no longer lists or accepts "epub:type="referrer" on a back link on a footnote. It is not deprecated but simply gone. It was dropped shortly after epub 3.0.1 was released if you look back of the history of ESSV docs.
When they removed "referrer" they added a draft "backlink" that nicely maps to the aria role="doc-backlink".
The new "backlink" has stayed as "draft" for literally years now.
If we add epub:type="referrer" on a footnote backlink we are technically violating the latest ESSV 1.1 spec.
If we add epub:type="backlink" on a footnote backlink, epubcheck in its INFO is listing it as unrecognized, but accepts then now long deleted "referrer".
Will you please modify epubcheck Info to accept epub:type="backlink" and remove the recognition of "epub:type="referrer" in order to meet the current ESSV recs?
Alternatively, since it is still draft perhaps allowing both epub:type="referrer" (even though no longer on the list - just for backwards compatibility) and epub:type="backlink" (even though still draft after many years). Or perhaps getting the ESSV to bring back "referrer"?
Unfortunately, Sigil is caught in the middle. If it autogenerates code to use the newer "backlink", epubcheck will say in its INFO setting that it is unrecognized. But if we use "referrer" we will be violating the ESSV 1.1 spec.
The Epub Structural Semantics Vocabuarly has undergone revision after the 1.0 release. The current ESSV version 1.1 no longer lists or accepts "epub:type="referrer" on a back link on a footnote. It is not deprecated but simply gone. It was dropped shortly after epub 3.0.1 was released if you look back of the history of ESSV docs.
When they removed "referrer" they added a draft "backlink" that nicely maps to the aria role="doc-backlink".
The new "backlink" has stayed as "draft" for literally years now.
If we add epub:type="referrer" on a footnote backlink we are technically violating the latest ESSV 1.1 spec.
If we add epub:type="backlink" on a footnote backlink, epubcheck in its INFO is listing it as unrecognized, but accepts then now long deleted "referrer".
Will you please modify epubcheck Info to accept epub:type="backlink" and remove the recognition of "epub:type="referrer" in order to meet the current ESSV recs?
Alternatively, since it is still draft perhaps allowing both epub:type="referrer" (even though no longer on the list - just for backwards compatibility) and epub:type="backlink" (even though still draft after many years). Or perhaps getting the ESSV to bring back "referrer"?
Unfortunately, Sigil is caught in the middle. If it autogenerates code to use the newer "backlink", epubcheck will say in its INFO setting that it is unrecognized. But if we use "referrer" we will be violating the ESSV 1.1 spec.