To do this, OpenType includes layout features—commonly known as
They’re not mandatory in English. But as a side effect, OpenType layout features have allowed type designers to add luxuries to their fonts—like alternate figures, small caps, ligatures, ordinals, and fractions—that had previously been difficult or impossible. That’s the good news.
The bad news is that merely adding an OpenType feature to a font doesn’t make it available to font users. Rather, the typesetting application also has to support the feature. Even though many OpenType-enhanced fonts are available today, software companies have been slow to upgrade their applications.
This bit of background just sets the stage for the annoying truth—that OpenType features can add a lot of typographic sophistication to your document, but you can only use a given feature if it’s supported by both the font and the application.
If you’re still interested in using OpenType features, some tips.
Designers of professional fonts (see font recommendations) will have downloadable specimen sheets that show you which OpenType features are supported by their fonts.
On the application side, the best overall OpenType feature support is found in professional page-layout applications like Adobe InDesign, Adobe Illustrator, and Quark Xpress.
All major desktop web browsers support OpenType features. Support is spottier among mobile web browsers.
Recent versions of Microsoft Word (≥ 2010 for Windows, ≥ 2011 for Mac) support a limited set of OpenType features (ligatures, alternate figures, and stylistic sets). But Excel and PowerPoint don’t support any. If you think this is ironic and a little sad given that Microsoft introduced the OpenType format in 1996, me too.
font-feature-settings followed by a list of features. Support is incomplete, however, so browser prefixes are still required.