@squawk
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    Interface CommBIdentityReply

    A DF21 Comm-B identity reply - the same squawk payload as SurveillanceIdentityReply (DF5), extended with a 56-bit MB field carrying an Enhanced Surveillance Comm-B register. Like SurveillanceAltitudeReply, this is a targeted response whose CRC is XORed with the responding aircraft's ICAO address rather than being a plain checksum - candidateIcaoHex needs cross-checking against known traffic before it can be trusted.

    interface CommBIdentityReply {
        candidateIcaoHex: string;
        commBRegisters: CommBRegister[];
        identActive: boolean | undefined;
        kind: "commBIdentityReply";
        squawk: string;
        squawkAlert: boolean | undefined;
    }
    Index
    candidateIcaoHex commBRegisters identActive kind squawk squawkAlert
    candidateIcaoHex: string

    Candidate 24-bit ICAO hex address, recovered from the CRC field - verify against known traffic before trusting it.

    commBRegisters: CommBRegister[]

    Every Enhanced Surveillance Comm-B register the MB field plausibly holds - see inferCommBRegisters. Empty if none matched.

    identActive: boolean | undefined

    True when the transponder's Ident (SPI) pulse is active, from the Flight Status field. Undefined for a reserved Flight Status value.

    kind: "commBIdentityReply"

    Discriminant tag identifying this as a decoded DF21 Comm-B identity reply.

    squawk: string

    The decoded 4-digit octal squawk code.

    squawkAlert: boolean | undefined

    True when the transponder is flagging a recent squawk code change, from the Flight Status field. Undefined for a reserved Flight Status value.

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