The Infamous Undefend Order

I was wondering if anybody could give me a good explanation as to what happens with this order? It is issued when the unit dies, when it is completely removed from the map, I think when its resurrected. What are all of the events that trigger the issuing of the "undefend" ability?

The reason I want to know is to have an exact definition of when the unit is "removed" and can no longer be revived, and they are completely removed from the game. I realized that there is a lot to the "undefend" ability that I do not know, and I would appreciate some light on the subject. Thanks.

You don't have to figure it all out, because Grim001 did it all for you in AutoIndex and the optional addon library.

The event that fires when a unit is indexed happens basically as soon as it is a valid unit. The one that fires when a unit is deindexed happens right before it stops being a valid unit. There's also events for resurection, load/unload (for transports), and a few others.

If you're just curious as to how it works, I'd ask grim some time in IRC.