I was watching Revenge of the Sith the other day and thought it was odd that the clones address Palpatine as My Lord.. I have never seen anyone address Palpatine as My Lord before, it seems odd to address the leader of a democracy as My Lord. Does this mean that the clones knew that Palpatine was Sidious(before the formation of the Empire)??
"My Lord" seems to be the official from of address for the Supreme Chancellor.
From Attack of the Clones
DAR WAC: The loyalist committee has arrived, my Lord.
Nute Gunway and other Separatist/Confederacy of Independent Systems characters also refer to him as "My Lord," Though it isn't clear if they call him this because he the Supreme Chancellor or because he's a Sith Lord or as a general term of respect.
NUTE : The invasion is on schedule, My Lord.
GENERAL GRIEVOUS: It will be done, My Lord.
COUNT DOOKU: I bring you good news, my Lord. The war has begun.
Mace Windu called Palpatine that, though I suspect he was being a bit sarcastic.
Mace Windu: The oppression of the Sith will never return! You, my lord, have lost!
Supreme Chancellor: [speaking as Darth Sidious] No... no... no! YOU WILL DIE!