The note on my approach plates says that ANNTS and CRUXX are for
turbojet aircraft and SCORR is for props.
Thanks for the link.

Rich wrote:
SCORR is THE departure gate for IFR piston aircraft leaving the Detroit
area southbound.
ANNTS and CRUXX are where Detroit wants you inbound from the South.
Toledo Approach has a good web page which details this:
http://www.tolatct.faa.gov/freq.htm
Look under "Preferred Routes"