system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] "Execute Order 66." - Was that just a secret trigger phrase, or did it have to come from Palpatine himself to work?

When Clone Order 66 was programmed into their inhibitor chips, was Palpatine banking on nobody else possibly knowing about the command, or is it baked into the instructions of the Order that only Palpatine can issue it? 

How would a Clone respond if the Order was issued by someone other than Palpatine? Would the effect kick in anyway, like the MCU Winter Soldier's trigger words? Would they just stand there confused as to what it means? Would they attempt to arrest the unauthorised speaker?
gpt
As of right now it appears that it *can* be triggered by others, but the only other one who activated it required using the Force to do so, whether that's actually a requirement or needed to in order bypass another requirement (e.g. being Palpatine) is unknown.