As I mentioned in a previous message, I've revised the MARC to MADS mapping to include the additional changes that Andrew Houghton suggested. I realized in mapping the 18X fields that there is no way to code in the MADS record that the heading is a subdivision only. This sort of construct of course is only relevant to particular subject thesauri, LCSH being one, but that information is needed for using the records in constructing a heading. There are a few other characteristics that we have no way to bring out. So I would propose adding something to MADS to code these sorts of things. I would call it "specialCharacteristics" and include the following: <authorization> The type of heading for which the authority is appropriate, e.g. subdivision. (Equivalent to MARC authority 008/09 code d) This distinction is needed for some thesauri, e.g. LCSH, MESH. <descriptionRules> The set of rules, if any, used to formulate the authority. e.g. AACR2. Equivalent to 008/10 There would probably be other characteristics that need to be added in the future. Are there others that are needed now? Rebecca