The Character That Isn't: A Tour of Unicode's Invisible Characters
Richard Gillam, Senior Software Developer, Language Analysis Systems, Inc., USA

Intended Audience: All

Session Level: Beginner, Intermediate

We normally think of a character encoding standard as encoding visible units of a writing system, but almost every character encoding standard has included "invisible" character assignments—ASCII, for example, has 33 invisible "control characters." Unicode has its own complement of invisible characters: not just the control characters it inherited from ASCII, but a set of its own "formatting characters," which have no visual presentation of their own, but causes differences in how the characters around them are displayed or interpreted. These characters are some of the most misunderstood in Unicode, and this talk will look at all of them, explain what they're for and why they're there, and what they mean to you.