Definition and index entry for "in-flow"

The term "in-flow" is used repeatedly, but I can't find a definition  
anywhere. I suggest appending something at the end of item 1 of 9.3  
(<http://www.w3.org/TR/CSS21/visuren.html#positioning-scheme>). For  
instance, something along the lines of

"Boxes in normal flow, and elements whose boxes are all in normal flow,  
are by definition /in-flow/."

(I don't know if this definition is actually accurate.)

And then make sure it has an entry in the index.

-- 
Øyvind Stenhaug
Core Norway, Opera Software ASA