nonlinear dependent sources
From the LTspice help files, in modeling nonlinear dependent sources (i.e., arbitrary behavioral voltage or current sources),
LTspice uses the caret character, ^, for Boolean XOR and “**” for exponentiation. … This means that when you import a 3rd party model that was targeted at a 3rd party simulator, you may need to translate the syntax such as x^y to x**y or even pwr(x,y).
From Helmut Sennewald:
I have seen a very few models using the syntax of Spice3
for resistor models. … The name of the resistor model is exchanged with the value.
RFDBCK 3 33 10K RMOD
RFDBCK 3 33 RMOD 10K