| First symbol | N | Type of modulation of the main carrier | Unmodulated carrier |
| First symbol | A | Type of modulation of the main carrier | Amplitude modulation, double-sideband |
| First symbol | H | Type of modulation of the main carrier | Amplitude modulation, single-sideband, full carrier |
| First symbol | R | Type of modulation of the main carrier | Amplitude modulation, single-sideband, reduced or variable carrier |
| First symbol | J | Type of modulation of the main carrier | Amplitude modulation, single-sideband, suppressed carrier |
| First symbol | B | Type of modulation of the main carrier | Amplitude modulation, independent sidebands |
| First symbol | C | Type of modulation of the main carrier | Amplitude modulation, vestigial sideband |
| First symbol | F | Type of modulation of the main carrier | Angle modulation, frequency modulation |
| First symbol | G | Type of modulation of the main carrier | Angle modulation, phase modulation |
| First symbol | D | Type of modulation of the main carrier | Amplitude and angle modulation |
| First symbol | P | Type of modulation of the main carrier | Pulse emission, sequence of unmodulated pulses |
| First symbol | K | Type of modulation of the main carrier | Pulse emission, pulses modulated in amplitude |
| First symbol | L | Type of modulation of the main carrier | Pulse emission, pulses modulated in width or duration |
| First symbol | M | Type of modulation of the main carrier | Pulse emission, pulses modulated in position or phase |
| First symbol | Q | Type of modulation of the main carrier | Pulse, carrier also angle-modulated during pulse |
| First symbol | V | Type of modulation of the main carrier | Pulse emission, combination of pulse modes or produced by other means |
| First symbol | W | Type of modulation of the main carrier | Combination of amplitude, angle, or pulse modulation modes |
| First symbol | X | Type of modulation of the main carrier | Cases not otherwise covered |
| Second symbol | 0 | Nature of signal modulating the carrier | No modulating signal |
| Second symbol | 1 | Nature of signal modulating the carrier | Single channel containing quantized or digital information without a modulating subcarrier, excluding time-division multiplex |
| Second symbol | 2 | Nature of signal modulating the carrier | Single channel containing quantized or digital information using a modulating subcarrier, excluding time-division multiplex |
| Second symbol | 3 | Nature of signal modulating the carrier | Single channel containing analog information |
| Second symbol | 7 | Nature of signal modulating the carrier | Two or more channels containing quantized or digital information |
| Second symbol | 8 | Nature of signal modulating the carrier | Two or more channels containing analog information |
| Second symbol | 9 | Nature of signal modulating the carrier | Composite digital and analog channels |
| Second symbol | X | Nature of signal modulating the carrier | Cases not otherwise covered |
| Third symbol | N | Type of information transmitted | No information transmitted |
| Third symbol | A | Type of information transmitted | Telegraphy for aural reception |
| Third symbol | B | Type of information transmitted | Telegraphy for automatic reception |
| Third symbol | C | Type of information transmitted | Facsimile |
| Third symbol | D | Type of information transmitted | Data transmission, telemetry, or telecommand |
| Third symbol | E | Type of information transmitted | Telephony, voice, or sound broadcasting |
| Third symbol | F | Type of information transmitted | Television or video |
| Third symbol | W | Type of information transmitted | Combination of information types listed above |
| Third symbol | X | Type of information transmitted | Cases not otherwise covered |