Classes of technical documentation may include:
Historically, most classes of technical documentation lacked universal conformity (standards) for format, content and structure. Standards are being developed to redress this through bodies such as the International Organization for Standardization(ISO), which has published standards relating to rules for preparation of user guides, manuals, product specifications, etc for technical product documentation. These standards are covered by ICS 01.110. Technical product documentation not covered by ICS 01.110 are listed in the subsection below.
A technical documentation is also required for medical devices following EU medical device regulation. Annex II, Technical documentation, and Annex III, Technical documentation on post-market surveillance, of the regulation describe the content of a technical documentation for a medical device. This includes e.g. information on the device specification, labelling and instructions, design and manufacture, safety and performance requirements, risk management, and the validatain and verfification of the device, inluding the clinical evaluation; and also information from postmarketing surveillance.
Some documentation systems are concerned with the overall types or forms of documentation that constitute a documentation set, as well as (or rather than) how the documentation is produced, published or formatted.
For example, the Diátaxis framework (which is mostly used in the field of software documentation ) posits four distinct documentation forms, corresponding to four different user needs: tutorials, how-to guides, reference and explanation. By contrast, DITA asserts five different "topic types": Task, Concept, Reference, Glossary Entry, and Troubleshooting, while RedHat's Modular Documentation system uses three "modules": Concept, Procedure and Reference.