2.24 Identification Request message (IDR): A message sent in the backward direction to request action regarding the malicious call identification supplementary service. Table 47/Q.763 Message Type: Identification request Parameter name Reference (subclause) Type Length (octets) Message type 2.1 F 1 MCID request indicators 3.31 O 3 Message compatibility information 3.33 O 3-? Parameter compatibility information 3.41 O 4-? End of optional parameters 3.20 O 1