For some examples of how the Library of Congress is adding additional data check out http://www.loc.gov/catdir/beat/beat.html One thing to consider is if the additional information would clog up the catalog. Adding a bibliographic essay for every author in every record would be redundant. Adding possible typos and synonyms for every subject heading would add unnecessary bloat. The ISBN ranges used by a publisher might be useful information but would not belong in every bib record for each of their publications. The associated authority records can handle that or some other method of linking. If the information is for the item in hand then it belongs in the bibliographic record. FRBR and an entity-relationship model clarifies things quite a bit, once it is worked through. Sincerely David Bigwood I suppose I'll have to implement an "author detail" page and appropriate database storage for it. The detail I'm looking for is probably not appropriate in a marc record.