Igitabo cyose gisohotse kigira umubare ukiranga,ni umubare ugizwe n’imibare 13, iri mu bice bitanu bitandukanye, buri gice kiba gifite icyo gisobanura.
ISBN (International Standard Book Number) ni umubare uranga igitabo; ugaragaza ubwoko bw’igitabo, igihugu cyasohokeyemo, ikigo cyemewe kuyitanga mu gihugu, inzu yasohoye icyo gitabo, ibitabo iyo nzu yasohoye n’umubare utangwa na ISBN ku rwego rw’isi.
Ni byiza ko igitabo kigira ISBN ifasha ku menya abanditsi n’abatuganya ibitabo mu gihugu, ifasha mu kugirango kizagurishwe mu gihugu no hanze yacyo, kugishyira mu isomero n’inzu zicuruza ibitabo, kugishyira mu mashini z’ikoranabuhanga, bifasha kugira ahantu wihariye hakuranga, usohorera ibitabo byawe haba ku rwego rw’igihugu cyangwa mpuzamahanga, ifasha kubona igitabo vuba. Amasomero, bibafasha kubika igitabo; kugitiza no kugitirura, kumenya amakuru y’igitabo biroroha.
Mu Rwanda ISBN itangwa na Rwanda Archives and Library Services Authority, ikigo gishinzwe ishyingura nyandiko z’igihugu n’amasomero. Ikayiha abafite inzu zisohora ibitabo,bakabasha kuziha abanditsi bashaka gusohora ibitabo.
Umubare umwe ugura amafaranga ibihumbi bibiri (2000), uzajya ku gitabo wasohoye na kopi zose uzasohora z’icyo gitabo.
Iyo uguze imibare icumi icyarimwe, wishyura ibihumbi icumi ( 10 000),ukazabasha kuyikoresha ku bitabo icumi, kuko umubare umwe ujya ku gitabo kimwe na kopi zacyo zose.
Igitabo kidafite ISBN ntabwo gishobora kugurishwa ku masoko mpuzamahanga.
