Lian -
 
You might start by looking at a letter/article  by  Nancy Seasholes in
the SHA Newsletter  back about 1989 (?).  I'm not sure about the exact
date but I believe it was when the  Newsletter was printed on blue paper.
 The current editor can probably tell you.
 
It's an interesting topic for discussion.
 
Cheers!
 
 
Carl Barna