Libraries use short, standardized codes known as symbols to identify themselves when participating in interlibrary loans, shared cataloguing, and networking.
Canadian Library Symbols
Library and Archives Canada (LAC) issues Canadian Library Symbols, which may be up to 8 characters long. The symbol comprises letters that identify the province or territory, the city, and the library. For example "AEU" stands for the Rutherford Library at the University of Alberta in Edmonton, Alberta.
Exceptions to the above rule are federal government libraries in the National Capital Region, which have symbols beginning with “OO.” For example, "OONL" is the symbol for LAC.
International Standard Identifier for Libraries
The International Standard Identifier for Libraries and Related Organizations (ISIL) (ISO 15511) is used for many purposes, including international interlibrary loan. ISIL is not normally used within Canada as a holdings symbol or interlibrary loan symbol.
To create an ISIL, Canadian libraries add "CA-" to the start of their Canadian Library Symbol issued by Library and Archives Canada. For example "CA-AEU" stands for the Rutherford Library at the University of Alberta in Edmonton, Alberta.
The library cooperative OCLC issues its own symbols when a library reports its holdings or buys an OCLC product.