Value Name,Long Name,Usable with,Mux,Reference sli,Slice Loss Indication,nack,IDENTICAL-PER-PT,[RFC4585][RFC8859] pli,Picture Loss Indication,nack,IDENTICAL-PER-PT,[RFC4585][RFC8859] rpsi,Reference Picture Selection Indication,"ack, nack",IDENTICAL-PER-PT,[RFC4585][RFC8859] app,Application layer feedback,"ack, nack",SPECIAL,[RFC4585][RFC8859] rai,Rapid Acquisition Indication,nack,IDENTICAL-PER-PT,[RFC6285][RFC8859] tllei,Transport-Layer Third-Party Loss Early Indication,nack,IDENTICAL-PER-PT,[RFC6642][RFC8859] pslei,Payload-Specific Third-Party Loss Early Indication,nack,IDENTICAL-PER-PT,[RFC6642][RFC8859] ecn,Explicit Congestion Notification,nack,IDENTICAL,[RFC6679][RFC8859] ccfb,Congestion Control Feedback,ack,IDENTICAL-PER-PT,[RFC8888]