From time to time the developers at ByWater will give each other guided tours of various sub-systems in Koha: Circulation, patrons, search, etc. Last week, we talked about holds, and as a side comment, Kyle mentioned the importance of biblio-level item types for holds: “If the biblio records don’t contain an item type, we won’t be determining the availability correctly”.
Holds use circulation rules to determine whether a title is available for hold. Circulation rules are based on
- Branch Code
- Patron Category
- Item type
These may use the wild card ‘*’ — I.e. All Branches, all patron categories or all item types, or you can specify a Branch code, patron category or item type.
For the purposes of circulation, this works perfectly — a borrower brings an item to the circ desk or self check-out machine, and it is immediately obvious which branch the patron belongs to, the item’s home branch, the patron category, and the item’s item type.
Holds are not so simple — in particular, with biblio level holds, items aren’t associated with the hold record until the hold is filled. This means, for the purposes of determining how many of a given item type that a patron can check out, Koha must check the biblio level item type… and if those are not set, or aren’t set consistently across the collection, you may see errors in the number of items that a patron can put on hold.