This is my understanding of the use of Item Types and CCodes based on the emails and list discussion. If my understanding is wrong - please correct it. If I have it clear then I think this would be useful for the Koha 3.0 Manual (certainly would have helped me!) Would love someone to please add in the marc fields where you would enter the information which will display in these fields(are we heading into mapping territory now?) BIBLIO LEVEL INFORMATION Search results display Biblio level info; which can include: * Format (book, DVD, video cassette) * Audience (children, young adult, adult) * Content (bibliography) * Material Type (using XLST search will display wee icons.) ITEM LEVEL INFORMATION The holdings table displays Item level info, which can include: * Item Types * CCodes * Shelving Location * Call Number ADVANCED SEARCH The Advanced Search interface displays either Item Types (with their associated icons) OR Collection Codes (with their associated icons). You cannot set both as Advanced Search options, although there is general agreement that this would be a cool enhancement. NOTES ON ITEM TYPES *set circulation policy * you must have item types * you don't have to have CCodes * can be used to define collections * can be OPAC advanced search points NOTES ON CCODESs * have no relationship to circulation policy * any number of CCodes can have the same the Item Type * are optional * are used to define collections * can be OPAC advanced search points NOTES ON CALL NUMBER Shows an items shelf position, can include alpha and numeric characters. NOTES ON SHELVING LOCATION Denotes a physical location ie a floor or building. (Not sure if this displays in OPAC or not.) GENERAL RULE OF THUMB *If you don't have to have CCodes to distinguish between Item Types and Collection Codes, then don't -- just use Item Types.* An example of when you would need CCodes, is where you have a policy which says borrowers may have no more than 10 AV items on loan at a time, but they may be taken from arange of different collections. So Item Type is set as AV and a bunch of CCodes are created: DVD, JDVD, Video, JVideo, CDROM, Audio Book on Tape, Teen Audio Book on CD, etc. A borrow a total of 10 AV materials from any of the CCodes related to Item Type=AV.