Opportunity modifier use in 3.5/PFRPG ruleset

[nickabbey]

In the 3.5 or PFRPG rulesets, does the [OPPORTUNITY] modifier get used by anything by default? From my reading of the manual, I should be able to use it in effects by coding them properly to be applied to [OPPORTUNITY] attacks. Otherwise, by default, do these rulesets apply any modifiers to rolls?

I'm asking because I want to bind a shift hotkey to an attack action, but that results in the [OPPORTUNITY] modifier being applied to the roll.
If that doesn't effectively DO anything to the roll, then the text can just be ignored and I can bind my key without worry of accidental cheating.

[Moon Wizard]

It's only for information in the chat log, and to allow opportunity specific effects.

Cheers,
JPG