While looking into the proper syntax for telephone numbers as links in microformats, I found a good discussion from 2005.

There’s a great discussion of telephone microformats and using the tel: protocol in an anchor tag.

Some simple examples might be:

<div class="agent vcard">
  <a class="email fn" href="mailto:jfriday at example.com">Joe Friday</a>
  <a class="tel"      href="tel:+1-919-555-7878</a>
  <div class="title">Area Administrator, Assistant</div>
</div>

Notice the use of the “tel:” in the href attribute. The only drawback I’ve found is that I get a lot of 404 errors in my stats because most clients do not have a telephone application associated with the “tel” link. This can be rather bothersome and result in this:

29	/experience/tel:1+408-656-2473
29	/quote/tel:1+408-656-2473
28	/advertising/tel:1+408-656-2473
28	/terms/tel:+1-408-656-2473

I haven’t decided yet if it is worth seeing these in my stats infavor of allowing skype, or other telephony VOIP apps to link through.