title: telprompt: allows less characters than the phone itself. Which?
body: <p>I'm using the address book of the iPhone to call numbers using telprompt:. A number with spaces and dashes doesn't work, while one with plus and numbers only does work. The iphone itself doesn't allow typing them, but synchronising with the mac gets me lots of (invalid?) phone numbers. Which characters are allowed, and why?</p>