XMP is an ISO standard for representing arbitrary metadata (about a file) as an RDF graph. It is possible to embed XMP metadata within several different file formats. PDF v1.4 included support for XMP by describing a standard way in which XMP metadata may be embedded within PDF files. Libreoffice supports generating PDF files, but currently seems to lack any way in which XMP metadata may be included within the resulting PDF files. The OpenDocument format, itself, supports embedding RDF metadata. One approach might be to use OpenDocument's support for RDF metadata to store the XMP metadata: the metadata that should be included in the PDF file. A disadvantage of this approach is that Libreoffice's support for ODF-embedded RDF metadata is currently rather poor (see bug #157451). An alternative approach might be to define the XMP metadata as an external file, and provide an option (within the PDF export dialogue) to identify the file. The contents of the file would then be embedded in the PDF file.. Although suboptimal, this approach may be feasible without waiting for bug #157451 to be resolved.
Created attachment 189903 [details] File properties exported to XMP fields There has been improvements in this area recently in bug 138792. You can test these in the nightly builds: https://wiki.documentfoundation.org/QA/Testing_Daily_Builds
Let's mark as duplicate of bug 138792 then. Paul, your testing of a daily build[1] and your feedback and comments would be very much appreciated in bug 138792. Thank you! [1]: https://dev-builds.libreoffice.org/daily/master/current.html *** This bug has been marked as a duplicate of bug 138792 ***