By Daniel Heuman
Originally published October 15, 2024. Updated November 3, 2026.
PerfectIt 6 introduced two important style updates: the Microsoft Writing Style Guide and the 18th edition of The Chicago Manual of Style.
We partnered with Microsoft to introduce the Microsoft Writing Style Guide in PerfectIt 6. It’s available to all users in Perfect 6 and PerfectIt Cloud at no additional cost.
The upgrade also gives CMOS Online Subscribers access to rule changes and revisions through PerfectIt
These were just some of the improvements included in the release. We also made changes to the overall user experience, which you can read about in our post on the other improvements introduced in PerfectIt 6.
Continue reading here to learn all about what we’ve done with styles.
1. Launching Microsoft Style for PerfectIt
The Microsoft Writing Style Guide is not just an internal guide used by Microsoft. It’s one of the most important styles for technical writers everywhere.
The Microsoft Writing Style Guide has its roots in the Microsoft Manual of Style for Technical Publications. That guide, first published in 1995, had a fourth edition in 2012. That makes it one of the oldest and most widely followed style manuals for technical writers. Today, Microsoft regularly updates the Microsoft Writing Style Guide online.
Like other good style manuals, the Microsoft Writing Style Guide doesn't try to cover everything. For issues that it doesn’t cover, it uses The Chicago Manual of Style as its reference style. PerfectIt allows CMOS Online subscribers to enforce Microsoft style as truly intended by combining The Chicago Manual of Style and the Microsoft Writing Style Guide.
To deliver the Microsoft Writing Style Guide in PerfectIt, we worked directly with Microsoft and took guidance from some of the original authors at Minden Editorial.
We're delighted to offer the style for free to all PerfectIt subscribers at no extra cost. If you’re interested in technical details for how we developed it, our analytical linguist has written about that here.
Book a live PerfectIt walkthrough to see the Microsoft Style Guide in action inside PerfectIt.
2. The Chicago Manual of Style, 18th Edition
If your social media feed is anything like mine, you’ve probably seen a big yellow book next to a smiling editor on more than one occasion in the past few months. That’s right!
The release of the 18th edition of The Chicago Manual of Style is big news in the editing world and we are proud to be a part of it.
There are already an incredible number of resources for learning about the changes in the new edition. Here are a few of the best:
The announcement of the new edition (including key changes) from University of Chicago Press.
An interview with Chief Reviser of the Manual in this Grammar Girl video.
Erin Brenner’s deep dive into the updates.
It’s not possible to include every change to the Manual in PerfectIt, but improvements that we have made to The Chicago Manual of Style for PerfectIt include:
Masthead capitalization: Automatically adjust capitalization to match hundreds of popular mastheads to ensure your titles reflect current standards without extra effort.
Title case: We’ve updated the style to fit the Manual’s new rules on title case.
Complex compounds and time zones: We’ve expanded our wildcard checks to include complex compounds and time zone accuracy for precision and efficiency.
Adverbial compounds: You’ll see updated hyphenation rules for more accuracy, making your text cleaner and more aligned with CMOS standards.
Our analytical linguist, Chris Ryder, had the pleasure of working directly with Russell Harper to deliver the style. You can read about all of the work and everything that has gone into the style here.
3. Improved styles
Alongside the Microsoft and Chicago styles, PerfectIt 6 introduced improvements to several other built-in styles.
Here's a look at some of those changes.
American Legal Style
Ivy Grey is the author of PerfectIt’s American Legal Style. She recategorized existing checks to make them clearer and added checks for the formatting of legal citations.
In addition, American Legal Style now includes more checks for writing style issues, such as reducing legalese and jargon, Latin and French phrases, incomplete edits, and subject-verb agreement. More terms and Bluebook updates are forthcoming.
Ivy is also the Chief Strategy & Growth Officer for WordRake, so we’re grateful to the entire team there for her assistance.
United Nations Style
We reviewed the updates to the United Nations Editorial Manual Online in order to bring PerfectIt’s checking right up to date.
The result is a significantly improved style that helps with enforcing documents across UN organizations.
European Union Style
We also made a few changes to our European Union Style.
Most users won’t notice the differences, but we’re thankful to the EU’s Directorate General for Translation for continuing to give us feedback that lets us improve how PerfectIt enforces the style.
Keeping PerfectIt and Its Built-In Styles up to Date
PerfectIt continues to ship updates beyond the original PerfectIt 6 release. These include changes to built-in styles, new checks, and improvements to performance and stability.
For instance, the April 2026 update to PerfectIt 6.6.5 included updates to EU Style, UN Style, WHO Style, Microsoft Style, and The Chicago Manual of Style. The October 2026 release, PerfectIt 6.8.7, added preferences for ellipses and included stability and performance fixes.
The PerfectIt release notes provide a complete history of these updates.
If you’re a PerfectIt user, you get all the latest updates for free, as long as your subscription remains active.
Windows users: Check the release notes for the latest version, then follow the instructions to download and install it.
Mac users: All styles improvements and other updates are applied automatically. Just run PerfectIt Cloud as normal and you’ll get the changes as soon as they go live.
If you’re not a PerfectIt user yet, you can book a live PerfectIt walkthrough and free trial for yourself or your team.