Unlike Morse Code abbreviations, the following signals are sent as a single character (no spacing between letters), indicated by an overline when written as text.
AA – Start new line (typically between lines in an address)
AR – End of message
AS – Stand by
BT – Pause; Break between sections of formal message
CT – Beginning of message, i.e. “Copy This” (also written as KA)
EEEEEEEE – Error, The correct text follows now.
IMI – I will now repeat the last word sent (typically used after an unusual or unexpected word). Also used to request a repeat of the last transmission, or as a standard question mark.
KN – Go ahead (specified station only)
SK – End of contact (also written as VA)
SN – Understood (also written as VE)
SOS – I am in distress (for emergency use only)