What are 'Layout Dims'?

I have googled the term and have come up with nothing. I found it here,
http://matthewjamestaylor.com/blog/perfect-3-column.htm whilst working with this template for my own webpage.

The code used is:

<p id="layoutdims">Measure columns in: <a href="http://matthewjamestaylor.com/blog/ultimate-3-column-holy-grail-pixels.htm">Pixel widths</a> | <a href="http://matthewjamestaylor.com/blog/ultimate-3-column-holy-grail-ems.htm">Em widths</a> | <strong>Percentage widths</strong></p>

#layoutdims {
clear:both;
background:#eee;
/* border-top:4px solid #000; */
margin:0;
padding:6px 15px !important;
text-align:right;
}



It appears to be some kind of special formatting for the <p> but I don't understand why he has called it 'Layoutdims'. I've seen this term used before. What does it mean? Am I safe to delete this line and replace it with a div to make a sub menu?

That is simply a name he picked and defined in his styles. He could easily have picked layout1, mylayout, etc.

PS. I'm guessing it is his abbreviation for layout dimensions...

Where did you get that code?

It has clear:both, so I assume it's clearing some float.

Thanks. Well, there is a left-floated list in the header, so I suppose he cleared the 'layout dims' so that this new strip of text could appear beneath. I got the code from his site, linked in my first post.