I've come across this time and time again, and i know i don't necessarily do this every time, but if you're working on a complex layout please please please comment your code! It makes future work for yourself, and other developers much easier.
In case it helps, this is the standard i tend to use:
<div id="header"> <h1>Site Title</h1> <p class="subtitle">Subtitle</p> </div> <!-- @end #header -->
Nice and easy, doesn't take much time to write and makes scanning through HTML much faster for everyone.
Right, as you were...