This International Standard specifies a basic set of commands for the interactive search of retrieval systems data and the types of response expected from the processing system. It is intended for use by designers and users of information retrieval systems, including computer-based library catalogues and computer-based database access and search facilities. This International Standard does not restrict or prohibit the use of other types of user-system interaction, such as menus or natural language interfaces, or the use of a "native" (non-standard) command language. NOTE 1 If the meaning of a standard command name conflicts with the meaning of a command name in the "native" language, the function of the standard command name is preferred. Some systems incorporate fewer functions than specified in this International Standard; others use additional functions. These additional functions may include added command names, operators or qualification and limitation techniques. It is important that additional functions and the type of response they generate conform to the general features and syntax set out in this International Standard