Last night I was reviewing definitions, and happened upon 
Chain Reaction in your August 7, 1997 version of the yellow book. 
In it, I read 
 Very Centers and the directly facing Outside dancers do 
 a Pass Thru as the End of the Center Line Counter Rotate........ 
 ^^^ 
I added a "s" to my 1997 book. 
I then took a look at the July 12, 1999 update. In it I found a 
handwritten "s" at the end of "End", but it's not clear if it was 
in the original printing or if I might have added it myself some 
years ago. 
Wanted to make sure you are aware of this minor typo so you can fix 
it someday, if you haven't already.