ISO/IEC 9995-5 (2009-10)

ISO/IEC 9995 defines a framework for the layout of all alphanumeric and numeric keyboards across the widest spectrum of today's and upcoming applications using keyboards. The functions to be performed by keyboards are grouped into three categories that correspond to the main physical sections of the keyboard.
Application of ISO/IEC 9995 in the design of keyboards will provide the user with a unified, predictable user-machine interface by dividing the keyboard into functional areas and sections and allocating functions to keys.
ISO/IEC 9995-5:2009 specifies the editing and function section and the division of that section into zones. It also specifies the cursor key zone (ZEF0) and the allocation of functions to its keys. Further, it specifies the arrangement, the number, and the location of the keys in the editing and function zone (ZEF1), as well as guidelines for the allocation of functions to the keys.