2 questions: lethal and precision bombardment

[friedmad]

can someone describe what these are? i've had stealth bombers before but have yet to see how i can choose a precision bombing mission or if its automatic what added effect it has.
also in the 1.21 patch, lethal bombardment is introduced. so i modded artillery to have this ability but nothing additional was gained - i still cannot kill unitswith artillery despite the editor help saying this is what lethal means.

please help.

<D>

 

[Tassadar]

Precision strike is done with stealth fighter or stealth bomber after you discover smart weapon.

i dont use 1.21 but i think letal bombardement if perform only when ennemy units have 1 h.p. left( near dead) i dont know if it work against ennemy artillery.