Normative and non-normative information

The DITA specification contains normative and non-normative information.

Normative information
Normative information is the formal portion of the specification that describes the rules and requirements that make up the DITA standard and which must be followed.
Non-normative information
Non-normative information includes descriptions that provide background, examples, notes, and other useful information that are not formal requirements or rules that must be followed.

All information in the specification is normative unless it is an example, a note, an appendix, or is explicitly labeled as non-normative.

The DITA specification contains examples to help clarify or illustrate specific aspects of the specification. Because examples are specific rather than general, they might not illustrate all aspects or be the only way to accomplish or implement an aspect of the specification. Therefore all examples are non-normative.