As reported on dspace-tech: https://groups.google.com/d/msg/dspace-tech/XaawNk47Gn8/gDp4oWQPAwAJ
These configurations are no longer used in DSpace 6.x:
In 5.x, these could be customized to change the default ordering of Bitstreams returned from a Bundle. See the code at: https://github.com/DSpace/DSpace/blob/dspace-5_x/dspace-api/src/main/java/org/dspace/content/Bundle.java#L72
In DSpace 6, we refactored our Java API to support Hibernate. These configurations were dropped in favor of explicitly ordering them via Hibernate here:
(This says to use the "bitstream_order" column from "bundle2bitstream", and that column is set based on the "sequence_id")
In DSpace 6, it is possible to still reorder Bitstreams (which changes the "sequence_id" and "bitstream_order"):
However, these configurations are no longer used, and may not be possible to easily re-enable in Hibernate.
We may wish to simply remove them from the dspace.cfg file, if a replacement feature cannot be found.