An objective of MARC Report 250 is to support the changes introduced by–
MARC21 Update No. 25--Bibliographic
MARC21 Update No. 25--Authorities
–announced by LC on December 18, 2017.
This update might be dubbed the “dollar $1 update”, since the main thrust of this update is to define $1 as a content designator for a Real world object URI (in far too many tags to list here).
One other interesting change (from the perspective of RDA) is the addition of a new tag
758 Resource identifier
which contains, in its definition, the following statement:
Resources thus identified may include, but are not limited to, FRBR works, expressions, manifestations, and items.
In addition, MARC Report 250 updates its codelists to include changes added by the following: