A little gem I came across on Wookieepedia just now. Why is it Order 66 you might have wondered? Because it was part of a set of 150 emergency contingency orders in place beginning with the creation of the Grand Army of the Republic (GAR in the article). Only a few have been written by EU writers, but they are:
Neat stuff, IMO. Random little things like this are why I appreciate Star Wars' expanded universe so much
Order 4
In the event of the Supreme Commander (Chancellor) being incapacitated, overall GAR command shall fall to the vice chair of the Senate until a successor is appointed or alternative authority identified as outlined in Section 6 (iv).
Order 5
In the event of the Supreme Commander (Chancellor) being declared unfit to issue orders, as defined in Section 6 (ii), the chief of the defense staff shall assume GAR command and form a strategic cell of senior officers (see page 1173, para 4) until a successor is appointed or alternative authority identified.
Order 37
Capture of a single wanted individual through the mass arrest and threatened execution of a civilian population. Follow-up directives include scenarios for body disposal of civilian casualties and suppression of communications.
Order 65
In the event of either (i) a majority in the Senate declaring the Supreme Commander (Chancellor) to be unfit to issue orders, or (ii) the Security Council declaring him to be unfit to issue orders, and an authenticated order being received by the GAR, commanders shall be authorized to detain the Supreme Commander, with lethal force if necessary, and command of the GAR shall fall to the acting Chancellor until a successor is appointed or alternative authority identified as outlined in Section 6 (iv).
Order 66
In the event of Jedi officers acting against the interests of the Republic, and after receiving specific orders verified as coming directly from the Supreme Commander (Chancellor), GAR commanders will remove those officers by lethal force, and command of the GAR will revert to the Supreme Commander (Chancellor) until a new command structure is established.
In the event of the Supreme Commander (Chancellor) being incapacitated, overall GAR command shall fall to the vice chair of the Senate until a successor is appointed or alternative authority identified as outlined in Section 6 (iv).
Order 5
In the event of the Supreme Commander (Chancellor) being declared unfit to issue orders, as defined in Section 6 (ii), the chief of the defense staff shall assume GAR command and form a strategic cell of senior officers (see page 1173, para 4) until a successor is appointed or alternative authority identified.
Order 37
Capture of a single wanted individual through the mass arrest and threatened execution of a civilian population. Follow-up directives include scenarios for body disposal of civilian casualties and suppression of communications.
Order 65
In the event of either (i) a majority in the Senate declaring the Supreme Commander (Chancellor) to be unfit to issue orders, or (ii) the Security Council declaring him to be unfit to issue orders, and an authenticated order being received by the GAR, commanders shall be authorized to detain the Supreme Commander, with lethal force if necessary, and command of the GAR shall fall to the acting Chancellor until a successor is appointed or alternative authority identified as outlined in Section 6 (iv).
Order 66
In the event of Jedi officers acting against the interests of the Republic, and after receiving specific orders verified as coming directly from the Supreme Commander (Chancellor), GAR commanders will remove those officers by lethal force, and command of the GAR will revert to the Supreme Commander (Chancellor) until a new command structure is established.
Neat stuff, IMO. Random little things like this are why I appreciate Star Wars' expanded universe so much