The CW characters can be divided into four groups (letter, digits, punctuation marks, other signs).
Beside the international CW characters there are some additional characters or also whole alphabets for some languages still.
These were not inserted however into the available enumeration.
If you write down the numbers, so use a string in the number zero (Ø) to tell apart the number from the character O.
The other signs will be send out without a space between the characters. An exception is the repetition (II).
Begin of message (KA)
End of contact (SK)
invite any station to transmit (K)
End of message (AR)
Please stand by (AS)
invite a specific station to transmit (KN)