Terminology

[Jhaelen]

The only real egregious ambiguity in terminology is the use of the word "attack."

And the unfortunate use of the keyword 'poison' which is also an energy type.

 

[Black Knight Irios]

And the unfortunate use of the keyword 'poison' which is also an energy damage type.

Which isn't that hard to distinguish:
If the power deals poison damage it refers to the damage type.
If the power has an effect it refers to the effect.
If a power has both poison damage and an effect the keyword refers to both.

Note that "effect" doesn't (necessarily) mean the effect entry in a power.

 

[Solvarn]

All paths lead to immunity/damage threads.