We're starting off using Koha to track "graded readers". Nearly all of these are in hierarchical sets. For example: Oxford====>Reading Tree===>Stage 1==>Kipper=>Readers: Oxford====>Reading Tree===>Stage 1==>Kipper=>Playscripts: Oxford====>Reading Tree===>Stage 1==>Kipper=>Big Books: Oxford====>Reading Tree===>Stage 1==>Kipper=>Teacher's guide: Oxford====>Reading Tree===>Stage 1==>Kipper=>Take-home cards: Oxford====>Reading Tree===>Stage 1==>Kipper=>Audio cassettes: Oxford====>Reading Tree===>Stage 1==>Kipper=>CDs: Oxford====>Reading Tree===Stage 1==>Biff & Chip=>Big Books: Oxford====>Reading Tree===Stage 1==>Biff & Chip=>Teacher's guide: Oxford====>Reading Tree===Stage 1==>Biff & Chip=>Take-home cards: Oxford====>Reading Tree===Stage 1==>Biff & Chip=>Audio cassettes: Oxford====>Reading Tree===Stage 1==>Biff & Chip=>CDs: Note the above is a sample list of *sets*. Within each set may be anywhere between three and twenty titles (or for some item types only one), and of course then there are usually multiple items of each title. Our shelving/numbering system (at least for this Item type) is to put all the books in order of reading difficulty level. I've created an alphanumeric local call number, which is the first part of the barcode that shows the level, then the set, then the titles, and then the copies. So Q010A04 means "the fourth copy of title A in set 010 in reading difficulty level Q". I've collected all my MARC records into text files by set. The file name for this set would be Q010.mrc, which would contain the MARC records for titles A, B, C, etc. I plan to import these one set file at a time, and if any MARC fields could be added to the records before importing to facilitate what I'm trying to do that would be relatively easy. I've done some initial reading of the MARC documentation and found some fields that seem designed to handle such relationships between separate titles (e.g. 440), but I only want to invest time in figuring out how to add them to my records if it will be useful within Koha after importing the MARC records. Some of the MARC records list multiple ISBNs reflecting some of this information, but they aren't complete, nor even consistent within a series! It is critical for people to see what related resources are available when they are browsing a given Reader in the OPAC, but some people want to just use the readers and ignore the rest, so I don't want to artificially create monolithic sets forcing people to borrow more than they need. As a separate but related issue, people placing orders to replenish our inventory should know which ISBNs to use for ordering - via set ISBNs rather than individually. Some ISBNs might be for six copies of one title within the series, others might be for one copy of each book in the series, another might be for six copies of each Reader plus one of each Big Book and take-home card plus one Teacher's Guide covering everything. And so on, with many permutations for each publisher. If necessary this information can be stored outside the system, but if it's possible for Koha to show these relationships that would be ideal. Even better would be for the budgeting and acquisitions modules to take advantage of such data. Regarding Koha's non-MARC database structure, I take it that Biblios are supposed to be exactly such "containers" for Biblioitems (e.g. the ISBN is an attribute of the Biblioitem, not the Biblio. However I'm not clear on how to use them as such in practice. My initial import will be for the Reader titles only, so I assume the Biblios thus created can function as the "master" record for subsidiary types where there is a simple relationship - ex a regular Reader has a corresponding Playscript, Bigbook or Take-home card. I also assume that I want to have separate Biblioitem records for each - in fact they are each separate Itemtypes, stored in different shelving locations. But what about when one Teacher's guide (or cassette/CD) covers all the books in a given set, or perhaps even a whole series comprising multiple sets (ex. at the Stage 1 level above)? When I import a new MARC record for such a "subsidiary" Biblioitem, how can I link it to the pre-existing "master" Biblio? They obviously won't have the same ISBNs. Is it possible to create "dummy Biblios" and then associate "real" ones as subsidiaries under them? If so, is it possible to have more than one level in the hierarchy? Phew! I really hope I'm making things more complicated than necessary, and there's a usual library management practice to handle this reflected in Koha and/or MARC information. I appreciate your even reading this far, much less actually attempting an answer <g> Hans