This International Standard specifies the requirements of a performance indicator for libraries and establishes a set of performance indicators to be used by libraries of all types. It also provides guidance on how to implement performance indicators in libraries where such performance indicators are not already in use. The list of performance indicators are summarized in Annex A and details given in Annex B. This International Standard provides a standardized terminology and concise definitions of the performance indicators. Furthermore, this International Standard contains concise descriptions of the performance indicators and of the collection and the analysis of data needed. This International Standard is applicable to all types of libraries in all countries. However, not all performance indicators are applicable to all libraries. Limitations on the applicability of individual performance indicators are listed for each performance indicator in Annex B. This International Standard does not specify performance indicators for all services, activities, and uses of the resources of the library, either because such performance indicators had not been proposed and tested at the time of formulation of this International Standard, or because they did not fulfil the criteria specified (see 4.2).