URL Scheme for Phone Call
phone-call, tel, url, url-scheme
Solution
The official standard for providing a telephone number as a URI is here: http://www.ietf.org/rfc/rfc3966.txt
It basically says use `tel:` as the prefix, and start the number with `+[international dialling code]` before the number itself. You can put non-numeric characters as separators (e.g. -) but they must be ignored. So a London (UK) number might be:
tel:+44-20-8123-4567
A New York (US) number:
tel:+1-212-555-1234
Problem
Much like the "mailto" URL prefix launches the user's default mail program and starts a new email with specified address, is there a similar URL scheme that would initiate a phone call? Perhaps "phone," "call," or "sip"? Incidentally, I'm targeting a platform that is using Cisco CUPS, so there may be a platform-specific way for me to initiate a call that is particular to Cisco, but I thought I'd ask the more general question first. However if anyone knows specifically how to programmatically initiate a call via CUPS, that would be great too.