I have the 5th printing. The only mention of a aux fuel tank is in the trouble shooting section;
If engine cranks but won’t start
Prolonged starter cranking (in excess of 10 seconds) could cause damage to the starter motor.
• Check the fuel gauge. You may be out of fuel. If the gauge shows that there is fuel in the tank, the trouble may be in the electrical system or the fuel system. If equipped with an auxiliary tank, be sure that the tank control switch is set for the tank with fuel and not on an empty tank.
I do see warnings & restrictions on the use of biodiesel though.
The NSA -- The only part of the government that listens.