ISO/IEC 23271:2012定义了公共语言基础设施（CLI），其中用多种高级语言编写的应用程序可以在不同的系统环境中执行，而无需重写这些应用程序以考虑这些环境的独特特征。它由六个分区组成。分区I描述了CLI的整体架构，并提供了公共类型系统（CTS）、虚拟执行系统（VES）和公共语言规范（CLS）的规范描述。它还提供了元数据的信息描述。分区II提供了元数据的规范性描述:它的物理布局（作为一种文件格式）、它的逻辑内容（作为一组表及其关系）和它的语义（从一个假设的汇编程序ILAsm中看到的）。分区III描述了公共中间语言（CIL）指令集。分区IV提供了CLI库的概述，以及将它们分解到配置文件和库中的规范。一个配套文件CLILibrary.xml被认为是该分区的一部分，但以XML格式分发，它提供了CLI库中每个类、值类型和接口的详细信息。分区V描述了在CLI生产者和消费者之间交换调试信息的标准方法。分区VI包含一些用CIL汇编语言（ILAsm）编写的示例程序、关于汇编程序特定实现的信息、CIL指令集的机器可读描述，可用于导出该汇编程序使用的部分语法以及操作CIL的其他工具、一组用于设计分区IV的库的指南以及可移植性考虑。

ISO/IEC 23271:2012 defines the Common Language Infrastructure (CLI) in which applications written in multiple high-level languages can be executed in different system environments without the need to rewrite those applications to take into consideration the unique characteristics of those environments. It consists of six partitions.

• Partition I describes the overall architecture of the CLI, and provides the normative description of the Common Type System (CTS), the Virtual Execution System (VES), and the Common Language Specification (CLS). It also provides an informative description of the metadata.


• Partition II provides the normative description of the metadata: its physical layout (as a file format), its logical contents (as a set of tables and their relationships), and its semantics (as seen from a hypothetical assembler, ILAsm).


• Partition III describes the Common Intermediate Language (CIL) instruction set.


• Partition IV provides an overview of the CLI Libraries, and a specification of their factoring into Profiles and Libraries. A companion file, CLILibrary.xml, considered to be part of this partition, but distributed in XML format, provides details of each class, value type, and interface in the CLI Libraries.


• Partition V describes a standard way to interchange debugging information between CLI producers and consumers.


• Partition VI contains some sample programs written in CIL Assembly Language (ILAsm), information about a particular implementation of an assembler, a machine-readable description of the CIL instruction set which can be used to derive parts of the grammar used by this assembler as well as other tools that manipulate CIL, a set of guidelines used in the design of the libraries of Partition IV, and portability considerations.