Which Edition of Your Citation Style Are You Using?

Editions below were checked against the publishers themselves in September 2026, not against library guides — a great many of which are still a full edition behind.

• APA — Publication Manual of the American Psychological Association, 7th edition (2020). No 8th edition has been announced.
• MLA — MLA Handbook, 9th edition (2021).
• Chicago — The Chicago Manual of Style, 18th edition (2024). Replaced the 17th, which ran from 2017.
• Harvard (Cite Them Right) — 13th edition (2025). There is no single "Harvard" authority, so your university's library guide is the final word; Cite Them Right is the most widely adopted independent standard.
• IEEE — IEEE Reference Guide, 2023 revision. IEEE dates its guide rather than numbering editions.
• AMA — AMA Manual of Style, 11th edition.
• CSE — Scientific Style and Format, 9th edition.
• Turabian — 9th edition, which is built on Chicago's 17th edition and therefore still includes the place of publication. This is the one case where the current edition of a style follows a superseded edition of its parent.

One change is visible at a glance, and it happens to be the change both Chicago and Cite Them Right made. Older editions required the publisher's city; the current editions do not.

If a book reference names a city, it follows the older edition. That single detail dates a reference faster than anything else on the page.

The 18th edition is a broad revision rather than a tidy-up. The changes most likely to affect a student paper:

• Place of publication is no longer required for books. Books published before 1900 are still usually cited by place alone.
• Singular they is accepted for a person whose gender is unknown or who uses it.
• Up to six authors are listed in a bibliography entry before et al. takes over.
• AI-generated content gets explicit guidance, including how to cite it and the copyright questions around it.
• Accessibility guidance for digital publications is substantially expanded.
• The shortened note remains preferred over ibid. for repeat citations — a preference Chicago introduced in the 17th and kept.

The 13th edition is a narrower revision. The headline change matches Chicago's: the place of publication is gone from references to books and conference proceedings, unless the location is genuinely needed to identify the publisher — early printed works, mainly.

Beyond that, the differences are small: punctuation tidying, updated handling of URLs and DOIs, and new examples for digital sources including generative AI.

Search for Chicago style today and a large share of the results — including pages that describe themselves as 2026 guides — still present the 17th edition as current. Two reasons, and neither is a conspiracy.

First, Chicago's editions are long-lived. The 17th ran for seven years, so a page written in 2019 was accurate for most of its life and nobody had cause to revisit it. Second, citation content is heavily templated and rarely re-checked; a page that has ranked for years is a page nobody wants to touch.

The practical consequence is that the top result is not evidence. Check the edition against the publisher, or against a tool that states which edition it implements.

Editions do not arrive everywhere at once. A department may run a module against the edition it wrote the handbook for, and a student mid-degree may be marked against the edition they started on. That is a legitimate reason to use an older edition deliberately.

Two rules keep you safe:

• The brief beats the manual. If your handbook names an edition, follow it, even when a newer one exists.
• Be consistent within one document. A bibliography that mixes editions is more obviously wrong than one that follows an old edition properly. Pick the edition, then apply it to every entry.
• Ask when the brief is silent. Most markers will simply say. If nobody will commit, use the current edition — it is the defensible default.

Every style in the default picker is the current edition of its guide: APA 7, MLA 9, Chicago 18, Cite Them Right 13 for Harvard, and the 2023 IEEE Reference Guide. The style picker names the edition it is using, so you are never guessing.

Older editions are available too, because sometimes they are the right answer. Sign in and the style picker opens onto the full CSL catalogue, where superseded editions — Chicago 17th, APA 6th, AMA 10th, CSE 8th — are listed and marked as older editions, with the current one named. Nothing is hidden; it is labelled.

• Signed out — the five built-in styles, always the current edition.
• Signed in — the full catalogue, with superseded editions clearly marked so choosing one is a decision rather than an accident.