MIL 188-110 serial 

Because M188-110 serial is used as a transparent modem, any kind of output can be expected. Mainly VT100 output (ASCII) is reported, 
but also ITA 2 will be possible.  
Symbol speed and transmission modes are selected automatically at the start of the decoding without further intention. 
IF-bandwidth of the receiver must be at least 3 KHz wide to enable undistorted decoding. 

A MIL188-110 ser signal together with an ALE signal 

Lead-in sequences (when viewed in ITA2 mode) useful for identification (especially in the absence of any ALE) of stations using the MIL-STD-188-110A 2400bd high-speed modem.

user Czech Diplomatic Service (variable speed frames, ASCII text & binary files) 
header BCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|} 
user US Coast Guard (always 600bd frames with Short Interleave, KG84 encrypted) 
header UUUUUUUyœ»V 
user Unidentified US Organization (always 1200bd frames with Short Interleave, KG84 encrypted) 
user Mexican Navy (variable speed frames, plain text and on-line encrypted) 
header ####0123456789
user Swedish Diplomatic Service, Venezuelan Army, Swiss Military (on-line encrypted) 
header .q 
user Romanian Diplomatic Service (variable speed frames, on-line encrypted) 
header xxxxxp\ and xxxxxq\