According to GB/T 1.1-2020 "Directives for Standardization - Part 1: Structure and Drafting Rules for Standardization Documents", the selection of normative elements in standards should follow the following three principles:

1. The Principle of Standardization Object

The principle of standardization object means that when drafting a document, it is necessary to consider the relevant content of the standardization object or field. This is to confirm whether the content to be standardized is a product/system, process, or service, or something related to a certain field. It is also necessary to determine whether it is a complete standardization object or a certain aspect of the standardization object, so as to ensure that the content in the normative elements is closely related to the standardization object or field. The standardization object determines the category of the object of the drafted standard, and it directly affects the composition of the normative elements of the document and the selection of its technical content.

2. The Principle of Document Users

The principle of document users means that when drafting a document, it is necessary to consider the users of the document. This is to confirm which group of users the document is aimed at and whether they are more concerned about the results or the process, so as to ensure that the content in the normative elements meets the needs of specific users. Different document users will have an impact on classifying the document as a specification standard, a procedure standard, or a test standard. As a result, the composition of the normative elements of the document and the selection of their content will vary accordingly.

3. The Principle of Purpose Orientation

The principle of purpose orientation means that when drafting a document, it is necessary to consider the purpose of document compilation. Guided by the confirmed purpose of compilation, a functional analysis of the standardization object should be carried out to identify the content or characteristics to be standardized in the document, so as to ensure that the content in the normative elements is selected to achieve the purpose of compilation. The purpose of document compilation determines the category of the purpose of the standard. Different purposes of compilation mean that the content or characteristics that need to be standardized in the normative elements are different. The more purposes of compilation there are, the more content or characteristics will be selected.

Note 1: If the purpose of document compilation is to promote mutual understanding, the category of the purpose of the formed standard is a basic standard. If the purpose is to ensure usability, interchangeability, compatibility, interoperability, or variety control, the category of the purpose of the formed standard is a technical standard. If the purpose is to protect health, ensure safety, and protect the environment, the category of the purpose of the formed standard is a health standard, a safety standard, or an environmental protection standard.

Note 2: Basic standards compiled with the purpose of promoting mutual understanding include functional types such as terminology standards, symbol standards, classification standards, and test standards. Standards compiled for other purposes include functional types such as specification standards, procedure standards, and guide standards.