Ray–I can not speak for the .30-06 Sleeve Marker rounds, but I have had experience with .50 BMG. We used standard rounds which were dipped after linking. We would take the entire string, usually 100 rounds and roll them up together. Then the entire roll was dipped, bullet point down, into a pan with about 3/4 inch of the lithographic ink, which came in about 10 colors. This was done perhaps 1 hour before loading into the aircraft guns.
There was no special designation for the dipped rounds. In fact, rounds in collectors hands with this ink still in place were most likely “Liberated” rounds as the standard procedure, if any rounds were left unfired (usually only if the gun jammed), was to wipe off the ink before returning the ammo to storage. The closest to a designation was to call them “Sleeve Marker” rounds as the target was a cloth or canvas cone shaped sleeve that was towed about 1000 yards behind the tow aircraft. The target sleeve was deployed from a underwing reel of cable and then reeled back in for landing.