The "media" attribute value extension has values added for engineering use.
Both have also been sent as INTERNET-DRAFTS:
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/draft-
ietf-ipp-finishings-fold-trim-bale-00.txt
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/draft-
ietf-ipp-media-engineering-00.txt
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-fi
nishings-fold-trim-bale-991020.doc
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-fi
nishings-fold-trim-bale-991020.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-fi
nishings-fold-trim-bale-991020.txt
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-fi
nishings-fold-trim-bale-991020-rev.doc
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-fi
nishings-fold-trim-bale-991020-rev.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-me
dia-engineering-991008.doc
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-me
dia-engineering-991008.pdf
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-me
dia-engineering-991008.txt
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-me
dia-engineering-991008-rev.doc
ftp://ftp.pwg.org/pub/pwg/ipp/proposed-registrations/attribute-values/ipp-me
dia-engineering-991008-rev.pdf