"id" attribute in microformats

Question

Is the "id" attribute allowed in microformats? Example (hCard microformat):

<div class="tel" id="voice">
  <span class="type">Voice</span>
  <span class="value">(206) 555-1234</span>
</div>
<div class="tel" id="fax">
  <span class="type">Fax</span>
  <span class="value">(206) 555-5678</span>
</div>

Answer 1

It is allowed but ignored by the standard. All properties have to be declared by classes:

Elements with class names of the listed properties represent the values of those properties.

Answer 2

Don't also hesitate to validate your markup: http://hcard.geekhood.net/