You will have to ask the developer (yo 1/14/2005 19:25). It is defined this way in the method #fullControlSpecs in the class #BooklikeMorph. It is the #ByteString value 179.I guess that it is an artifact of some changes that have been made over the years.

I am still learning Squeak. I discovered this by searching for the string in the control's help bubble, 'More Controls'.

Note: On Win 7 the behavior is different than it it on Mac OS! On Win the character changes when I mouse it, On Mac, it does not.

Hopes this helps!

jrm