[PROCON]

You Marines called your DI's, "Yes Sir!"

Army DI's were, "Yes, Drill Sergeant!"

[stylin19a]

My memory is fading, but I seem to recall we referred to them as: Drill Instructor or Senior Drill Instructor but we couldn’t call them that directly.

Directly, it was “Sir” to start and “Sir” to end.
as in:
“sir, yes sir”, “ sir, no sir”, “ sir, aye-aye sir” and
“sir, the private doesn’t know, sir.”