ISBN is an internationally recognized system whereby code numbers are assigned to books for easy identification and speedy exchange of information among publishers and all segments of the book industry and allied sectors. Specifically, it is a unique and unchangeable code number assigned to one title, one binding or edition of a published work.
ISSN is an international identifier for serials and continuing resources in the electronic and print worlds. It can be assigned to any serial or continuing resource whether past, present or to be published in the foreseeable future whatever the medium of production (e.g. print, online, CD-ROM, etc.).
ISMN is a unique 13-digit number for the identification of all printed and digital music publications i.e. notated music such as scores, vocal scores, sheet music, anthologies of music, music part or separate parts for a particular instrumentation from a specific publisher or producer. It is compatible with the international EAN-13 digit barcode, an internationally recognized system whereby code numbers are assigned to facilitate international cooperation and information exchange.