In a doc, (Office 2003, Word, XP (toolsoptions"All" checked visible) there
is a square black dot to the left of the text boundary -- one for each
paragraph with heading styles 1-4. No dot for headings 5- and lower. I
know I've seen something about the dot somewhere, but can't find it. What's
the dot about and what, if anything, does it do?

Ridge