CNet/4 features a new command interface for reading messages and traversing different subboards and subdirectories. With CNet/4, The slash (/) must pre-empt the subboard number when you wish to go to a new subboard. (ie /4 to go to subboard number 4 on the list).
Entering a number x while in CNet/4 mode will tell CNet you wish to read message number x. You may still use Rx (where 'x' is the number of a message) also.
CNet/3 mode forces CNet/4 to switch to a pseudo 3.x emulation. With this emulation enabled, you will enter a number alone to move to a subboard. When reading messages in CNet/3 mode, you are required to enter an 'R' before the message number. ie. "R5" to read message number 5 in the current subboard.