i don't have mark-flow

i have now 2,9rc-1, but i dont have mark-flow command.

Can anybody know, what is different, or, how can i use it.???

in 2.9 there is no mark flow. there it is called new-packet-mark:
http://www.mikrotik.com/docs/ros/2.9/ip/mangle||0.4734982332155477