Section 3.9 of the Fedora Specification defines a new interaction pattern for external content. The Fedora 4.x interaction is defined here: https://wiki.duraspace.org/display/FEDORA4x/External+Content. In a short the external content handling interaction is triggered via the use of a special variation of the ContentType header. The new interaction, defined in https://fcrepo.github.io/fcrepo-specification/#external-content , uses a link header instead.
This task is to remove the old pathway for creating external binary (LDP-NR) content, ie using in a PUT or POST with the following header:
Content-Type: message/external-body; access-type=URL; URL="http://example.com/external/content/file"
and replace it with the new handling:
Link: <http://example.com/external/content/file> ;
Any Content-Type header in the request should be ignored.
When serving requests for the the newly created resource servers should use HTTP redirect (302) responses with the Content-Location header specifying the external content location.