What version of Unified Office Format spec does LibreOffice 5.x support?

Hi Libre folks,

Is there any announcement/documentation from Libre on which version of the UOF spec does it support (both read and write)? UOF turned 2.0 since 2011.

So is it UOF 1.0 or 2.0?

We work with UOF 1.0 (circa 2006) via XSLT filters for import of UOF to ODF, and export from ODF to UOF for Text, Spreadsheet and Presentation

Last I recall of discussing UOF 2.0 was that it had never been published as an accessible standard and had died on the vine.

=-ref-=
http://nabble.documentfoundation.org/UOF-v2-0-the-PRC-national-XML-standard-for-Chinese-Office-documents-what-to-do-with-it-in-LibreOffic-tc4128745.html

State of the UOF 1.0 filters can be reviewed in source:
http://opengrok.libreoffice.org/xref/core/filter/source/xslt/import/uof/
or
http://opengrok.libreoffice.org/xref/core/filter/source/xslt/export/uof/

Some notes/comments in a couple of LO Bugzilla issues:
https://bugs.documentfoundation.org/show_bug.cgi?id=50430
or
https://bugs.documentfoundation.org/show_bug.cgi?id=73292