a aref="tel code example
Example 1: html telephone link
One click should open the phone dialler and input the number to be called.
<a href="tel:5551234567">Call (555)123-4567</a>
Example 2: html make phone number callable
Area code with dashes, 1 and + sign
<a href="tel:+1-555-555-1212">555-555-1212</a>
Area code with no dashes, 1 and + sign
<a href="tel:+15555551212">555-555-1212</a>