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.