Spurious "<abbr> inside value title attribute will be ignored." warning

I have a page with div like this:

  <div id="myDiv" class="vcard">
    <h3 class="fn n">
      <span class="given-name">Jane</span>
      <span> </span>
      <span class="family-name">Doe</span>
      <span>, </span>
      <abbr title="Doctor of Dental Surgery" class="honorific-suffix">D.D.S.</abbr>
    </h3>
    <div style="display:none" class="category">dentist</div>
  </div>

This seems to be correctly producing the following:

Card source	#myDiv
Category	dentist
Formatted name	Jane Doe, D.D.S.
Given Name	Jane
Family Name	Doe
Honorific Suffix	Doctor of Dental Surgery

However, there is also the following message:

:warning:

  <abbr> inside value
  title attribute will be ignored.

Neither the abbr nor the title are being ignored, it seems.

It may be just poorly worded message.

If I remember correctly it was meant to warn that:

<abbr class=fn title=t>v</abbr>

Has value t, but

<span class=fn><abbr title=t>v</abbr></span>

Has value v.