Professional associations produce style guides in order to standardise citation methods in their field. These standards should be adhered to, unless there is a very good reason to use or create another style.

Below is a list of some professional association style guides. Corresponding CSL styles for most of them are at the Zotero style repository.

If you know of other official association style guides, please add them
(this is a wiki, and you are welcome to contribute).

Many style guides are in the form of books which are not freely available; your library may hold a copy, and there are also webpages like this and this which give free and simple guidelines on using the styles correctly.

The use of unique identifiers, such as the DOI, is increasingly encouraged in citation styles.

• ISO 690 (Wikipedia page)
• ISO 832

• American National Standards Institute & National Information Standards Organization (free PDF available)
• British Standards Institution - standards BS 1629:1989, BS 5605:1990, BS 6371:1983
• Commonwealth of Australia

• Bluebook Standard System of American Legal Citation
• Indigo Book: A Manual of Legal Citation
• Oxford University Standard for Citation of Legal Authorities (OSCOLA) (free)

• Modern Languages Association (Wikipedia page)
• Unified Style for Linguistics (PDF, free)
• American Political Science Association (PDF, free)
• Modern Humanities Research Association

• Council of Science Editors
• American Chemical Society (Wikipedia page)
• American Institute of Physics (PDF, free)

• IEEE (PDF, free)

• American Psychological Association (Wikipedia page, free APA tutorial)
• American Sociological Association (PDF, free)
• American Anthropological Association (free)

• American Medical Association
• International Committee of Medical Journal Editors (free) based on:
• National Library of Medicine (free)

In addition a number of commercial style guides are published, for example.

• Chicago Manual of Style
• Turabian

More examples of styles in use in particular fields can be seen at the Wikipedia page on Style guides