OK, he probably refers to the TIGER Fibel ("TIGER-handy-quick-reference") written in 1943 and must have 4 every tanker.
I actually printed it out and binded it to a little booklet, and referred to it during gunnery training in TvT. Makes ya aprreciate the accuracy of the game even more.
Anyways heres the link:
http://tiger1.info/fibel/
Enjoy but be advised its in german....
Cheers, trebb
NB. I have seen better copies online, but lost the link. If not happy, a google for Tiger Fibel may help.