ISO/IEC 9995-2 (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 9995-2:2009 specifies the alphanumeric section of a keyboard and the division of that section into zones; the arrangement, the number, and the location of the keys in the alphanumeric zone ZA0 of the alphanumeric section; and the layout and allocation of several control functions to the keys in the function zones of the alphanumeric section.
The primary layout within the alphanumeric zone is established in most countries by a national standard or by national usage. ISO/IEC 9995-2:2009 provides allocation guidelines.