ISO/IEC 9995定义了一个框架，用于在当今和未来最广泛的使用键盘的应用程序中，所有字母数字和数字键盘的布局。键盘要执行的功能分为三类，分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为用户提供统一、可预测的用户-机器界面，方法是将键盘划分为功能区域和部分，并将功能分配给按键。 ISO/IEC 9995-8:2009规定了键盘数字区ZN0键的字母分配，该键盘在“1”中分配了10位数字0到9- 2-3“布局。ISO/IEC 9995-8:2009中规定的布局适用于信息技术设备键盘的应用，其中使用字母而不是数字来记忆数字信息。

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 9995-8:2009 specifies the allocation of letters to the keys of the numeric zone ZN0 of a keyboard which has the ten digits zero to nine allocated in the "1-2-3" layout. The layout specified in ISO/IEC 9995-8:2009 is intended for applications of information technology equipment keyboards where letters instead of digits are used for the mnemonic retention of numeric information.