Wednesday, April 4, 2012

Letters In Place of Numbers in Phone Number Links on Mobile Phones

Part of an upcoming project involves displaying office phone numbers on a web page such that, if the page is being viewed on a smartphone, tapping on the number pulls up the phone's dialing program with the number filled in and the user just needs to start the call.

Some of the phone numbers in question use letters in place of numbers (like "1-800-555-CFML" as an example) and I wondered if such numbers would work.

The answer is "probably not," as it's not something supported in the spec (the spec being RFC3966).  Tried it on my Galaxy Nexus anyway: no dice.  So I'll have to convert any such letters to their numerical equivalent

Some other things I learned today:

  • Per the W3C recommendation regarding "click-to-call" links, you should always include the "+" sign in front of the number to support international callers ("+1-800-555-CFML").
  • You can also use "." as a separator instead of a "-", and you can get away with using both types of separators in the same number.