He is often confused with Captain Tay or Sergeant Tay. In fact, Sergeant Tay was how the character was named in the script. In the film and novelization, however, it was changed to Lieutenant Tay. People often confuse his character with Captain Kinh, a Vietnamese river pirate. By sheer coincidence, there was also a commander in the POW camp Tay worked at that was named Captain Vinh, who Rambo burned alive in a cornfield with many of Tay's men later in the film. The two characters are not to be confused with each other and most people accept the fact that his rank is Lieutenant.
He led many of Podovsky's men to try and kill John Rambo. He and his men later returned and killed Co by shooting her with AK-47s. Rambo killed Tay's men and he ran off like a coward.
Later, Tay returned and confronted Rambo a final time. Rambo was fighting Podovsky's forces with explosive arrows at the time. Tay got a distance away and shot at Rambo with his AK-47 and when that ran out of bullets, he used his Zastava pistol instead, which he also emptied in a futile attempt to kill Rambo. But after Tay missed for the final time with his pistol, Rambo obliterated him with an explosive arrow to the abdomen, blowing him to bloody shreds and killing him.