One thing that seems to be missing in the discussion of core elements for relationships in RDA is the massive overhaul to relationships that exist in the entire second half of RDA, and continued in the appendixes on relationship designators.
RDA is a powerhouse when it comes to defining and enabling relationships, and there's an elegant simplicity and consistency to its approach. The AACR-MARC 1XX/240/7XX/8XX main/added entry and 5XX see-ref limitations for relationships look like a well lived-in doghouse in comparison (and certainly not easier to understand than RDA for novices). Thomas Brenndorfer Guelph Public Library
