The system of Location Codes enables unequivocal identification of institutions. Although their names and addresses may be changed over time, the Location Code  as unique identifier used by the National Library of the CR remains  unchanged. Being directly linked to national electronic and card  union catalogues, it is used also for loans of documents by means of the interlibrary loan service.

The Location Code is a combination of three alphabetic letters and three digits where each character has a special meaning:

The capital letters in the first two positions mean the geographical location (derived from commonly used abbreviations of the former main district towns), the  capital letter in the third position indicates the type of the library:

A – central libraries

B – libraries of the Academy of Sciences of the CR

C – libraries of other institutes

D – university (academical) libraries

E - libraries of state administration, public institutions, cultural, interest and social organizations, hospitals and other medical and health care organizations, and church libraries

F - libraries of firms, companies, plants, factories and project organizations

G - public libraries and school libraries

The numerical part of the Location Code represents a reference numbers of a particular  library. It is formed by three-digit numbers from 001 to 999 where numbers 001 - 499 represent libraries based in main district towns and numbers 500 to 999 libraries in other cities and villages of the district..

e.g.: CLG001 = Town-library of Česká Lípa

(CL =  Česká Lípa district,  G = public library,  001  =  library based in the main district town)

BNE701 = Rehabilitation Center Kladruby

(BN = Benešov district,  E = health care organization, 701 = medical library based out of the main district town)

Abbreviations - characters in the first part of the Location Code expressing geographical specification:

AB = Praha,  BE = Beroun,  BK = Blansko,  BN = Benešov,  BO = Brno,  BR = Bruntál, BV = Břeclav, CB = České Budějovice,  CH = Cheb,  CK = Český Krumlov,  CL = Česká Lípa,  CR = Chrudim,  CV = Chomutov,  DC = Děčín,  DO = Domažlice,  FM = Frýdek Místek,  HB = Havlíčkův Brod,  HK = Hradec Králové,  HO = Hodonín,  JC = Jičín, JE = Jeseník,  JH = Jindřichův Hradec,  JI = Jihlava,  JN = Jablonec nad Nisou, KA = Karviná,  KH = Kutná Hora,  KL = Kladno,  KM = Kroměříž,  KO = Kolín,  KT = Klatovy,  KV = Karlovy Vary,  LI = Liberec,  LN = Louny,  LT = Litoměřice,  MB = Mladá Boleslav,  ME = Mělník,  MO = Most,  NA = Náchod,  NB = Nymburk,  NJ = Nový Jičín,  OL = Olomouc,  OP = Opava,  OS = Ostrava,  PA = Pardubice, PB = Příbram,  PE = Pelhřimov,  PI = Písek,  PN = Plzeň,  PR = Přerov,  PT = Prachatice, PV = Prostějov,  RA = Rakovník,  RK = Rychnov nad Kněžnou, RO = Rokycany,  SM = Semily,  SO = Sokolov,  ST = Strakonice,  SU = Šumperk,  SV = Svitavy,  TA = Tábor,  TC = Tachov,  TP = Teplice,  TR = Třebíč,  TU = Trutnov,  UH = Uherské Hradiště,  UL = Ústí nad Labem,  UO = Ústí nad Orlicí,  VS = Vsetín,  VV = Vranov, VY = Vyškov,  ZL = Zlín,  ZN = Znojmo,  ZR = Žďár nad Sázavou