The compatibility anchors inserted when a header contains special characters are wrapped in <p> tags. The wikitext
áàâ
is rendered as
<p><a id=".C3.A1.C3.A0.C3.A2" name=".C3.A1.C3.A0.C3.A2"></a></p>
<h2><span class="mw-headline" id="áàâ">áàâ</span></h2>
Why are the <p> tags there? Probably because only block elements are allowed as children of the bodytext. But these paragraphs can affect rendering because they have top and bottom margins (which happen to collapse with other margins most of the times, but not necessarily always).
I'd prefer one of the following:
<div id=".C3.A1.C3.A0.C3.A2"></div>
<h2><span class="mw-headline" id="áàâ">áàâ</span></h2>
or
<h2><a id=".C3.A1.C3.A0.C3.A2" name=".C3.A1.C3.A0.C3.A2"></a>
<span class="mw-headline" id="áàâ">áàâ</span></h2>
Besides that, I don't see a reason for the name attribute? It is not valid in HTML5 (looks quite odd if something that has been added because of HTML5 breaks validation) and only needed by browsers of the Netscape 4 era. The real headers don't have named anchors either, so that's rather pointless.
Version: unspecified
Severity: enhancement