i personally won't compete for sig-fail of the week, but suppose i post
the following wiki-text on a page:
<span style="background:pink;"> [[talk]] </span>
two tidyings will occur during "normal" parsing, to wit...
the nesting of tags <font> and <a> is inverted:
<a href="/wiki/Name" title="Name"><font color="green">name</font></a>
spaces are moved outside the <span>:
<span style="background:pink;"><a href="/wiki/Talk" title="Talk">talk</a></span>
however, the signature preview on special:prefs does not reflect either
of these changes, probably creates other surprises as well.