4.
Signal transmission method
5.
Spacing training technique
6.
Alternating dot dash method
7.
Morse code input device
8.
Calling any station signal
10.
Phonetic morse equivalents
11.
Interval between characters
12.
Relative length of signals
13.
Frequency drift signal
14.
Frequency limit marker
15.
Competitive communication event
16.
Skill improvement technique
17.
Electronic keying method
19.
Relative signal duration
20.
Communication language
21.
Transmission technique
24.
Original communication method
25.
Traditional input device