Is there a rule against using "_" in Master Script variable names?

[LeeJaeYoung]

Is there a rule against using "_" in Master Script variable names?

In_WallThk This will result in 0 in the 2d script.

[julienK]

It works fine for me.

master script:

test_var = 3

2d script:

print test_var

i get the right value

[LeeJaeYoung]

I keep having the value of 0, so I am changing it to InWallThk and proceeding.