9 pin cable from radio to RC

Do I have to use the supplied cable, or can I make my own shorter more flexible cable out of flat cable?

<R67> …and 9-pin cables shall not be tampered with, modified, or adjusted in any way.

<R71> Ribbon cable … may be used to connect signal lines to the 9 pin ports on the Robot Controller.

The space I have to mount the RC in is kind of funky, and If I have to use the bulky supplied cable, our RC is going to have to be mounted vertically or something…

You will probably want to check out this Q&A system answer, which addresses how the radio modem must be connected to the RC.

-dave