as per DB sir post there isnt any sub-quota or atleast #lowerberthquota in CK. but then we have come across many instances where contradiction to above point has happened.
e.g. check this /pnr/post/1250245 , here CKWL#4 confirms, but CKWL#16 falls by only 1 place instead of falling by 4 places ,
and then check this /pnr/post/1113457
....
there...
more... are many other PNRs which espouse doubts over lowerberthquota getting preference in CK too, but above 2 examples have supportive evidence too.