Confused with length units em,en, & ex in Margin

In a margin specification (or padding)  I'm assuming the en and em 
measurements are based on the font for the current element.  Is this 
correct?
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| Mortar: Advanced Web Development <http://bigpic.com/mortar/>
| Neil St.Laurent  neil@bigpic.com
| Big Picture Multimedia

Received on Tuesday, 22 July 1997 17:40:25 UTC