ISO/IEC 9995为所有字母数字键盘和数字键盘的布局定义了一个框架，涵盖了当今和未来使用键盘的最广泛的应用。要由键盘执行的功能被分成三个类别，这三个类别对应于键盘的主要物理部分。ISO/IEC 9995在键盘设计中的应用将通过将键盘划分为功能区和部分并将功能分配给按键，为用户提供统一的、可预测的人机界面。ISO/IEC 9995-4:20 09指定了键盘的数字部分以及该部分的分区。它规定了数字部分的数字区ZN0和功能区ZN1至ZN6中的键的排列、数量和位置，以及对键的功能分配。数字区ZN0将用于诸如文本和数据处理、一般办公环境、银行业务、销售点(POS)、远程信息处理服务、电话设备、家用电子系统、机械和设备的数字控制以及个人识别号(PIN)的输入等应用的键盘中。功能区ZN1将用于用于诸如数据输入、文本和数据处理以及一般办公环境的应用的键盘中。

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 9995-4:2009 specifies the numeric section of a keyboard and the division of that section into zones. It specifies the arrangement, the number, and the location of the keys in the numeric zone ZN0 and in the function zones ZN1 to ZN6 of the numeric section, as well as the allocation of functions to the keys.

The numeric zone ZN0 is to be used in keyboards for applications such as text and data processing, general office environment, banking, point of sales (POS), telematic services, telephony apparatus, home electronic systems, numerical control of machinery and equipment, and input of personal identification number (PIN). The function zone ZN1 is to be used in keyboards for applications such as data entry, text and data processing, and general office environment.