As far as i am aware and from a bit of experience with this myself!
Each strip of paper/white tape has the layout of what instrument/noise is on each channel of the mixing desk per song.
So say Rik loads the settings to Jumbo into the desk he can lay the strip of paper across the desk and at the bottom of each channel it will say 'Bass' or 'Synth' etc so he and Karl or Darren know what instrument is on each channel and can tweak some levels or mute a channel in safe knowledge that it will be the instrument they have written on the paper!
Hope this makes sense!!
Cheers,
Jez.
www.myspace.com/buji