I know because my Late Father volunteered to go to Nam as a PIO for 6 months that year. He covered those units, told me about them and showed me the pictures he took of them.
He also told me about trying to give the stories and pitctures of them to one the bureau chiefs in Siagon. The chief refused to take them because they didn't show the Viet Nam War he wanted the American public to see. That treasonous bastard's name was Dan Rather.
BIG CORRECTION. It was 1969, not 1966!
In general, most of the NGs who served in Nam missed too many meetings. A smaller number simply volunteered.