What is qt/dqt decode?

CTCSS/DCS Encode/Decode (also know as Privacy Tones or Codes). Kenwood TKR-750-850 Manual Online: channel information, Reception Frequency, Transmission Frequency, Qt/Dqt Decode, Qt/Dqt Encode. Dec QT/DQT means receive CTCSS/DCS, only when you don't want to receive non CTCSS/DCS or different CTCSS/DCS signals, you can set it. Encoder/decoder function uses QT/DQT to segregate talk groups, so users only hear calls from their own group.