Extended combat training
ECT in medical terms means electroconvulsive therapy.
This is not used in the U.S. military.
Bronetransporter
Measures of central tendency are the mean, median, range, mode ect.
To be forced into service
It means to be armed
secured area
Died While Missing
north Atlantic treaty organization
It is "Basic Active Service Date"
member of a State national Guard Unit
If you're talking about military terms, it stands for Letter Of Notification