#scenariorepository.h (the one this PR will change)
    struct ScenarioIndexEntry
    {
        ...
        // Objective
        uint8_t ObjectiveType;
        uint8_t ObjectiveArg1;  // years
        int64_t ObjectiveArg2;  // money or excitement
        int16_t ObjectiveArg3; // guests or rideID or coasterLength
        ...
    };

#rct2.h
    struct S6Info
    {
        ...
        uint8_t ObjectiveType; // 0x02
        uint8_t ObjectiveArg1; // 0x03
        int32_t ObjectiveArg2; // 0x04
        int16_t ObjectiveArg3; // 0x08
        ...
    };

#rct2.h
    struct ScoresEntry
    {
        ....
        int8_t ObjectiveType;
        int8_t ObjectiveArg1;
        int32_t objectiveArg2;
        int16_t objectiveArg3;
        ...
    };


#scenario.h
    uint8_t Type;
    uint8_t Year;
    union
    {
        uint16_t NumGuests;
        StringId RideId;
        uint16_t MinimumLength; // For the "Build 10 coasters of minimum length" objective.
    };
    union
    {
        money64 Currency;
        ride_rating MinimumExcitement; // For the "Finish 5 coaster with a minimum excitement rating" objective.
    };