Unless whatever is reading the value requires a hex number, you could also use decimal values:
#define RN4020_EXTENDED 128 // 0x80
#define RN4020_AUTENTICATED 64 // 0X40
#define RN4020_INDICATE 32 // 0X20
#define RN4020_NOTIFY 16 // 0X10
#define RN4020_WRITE 8 // 0X08
#define RN4020_WRITE_WITHOUT 4 // 0X04
#define RN4020_READ 2 // 0X02
#define RN4020_BROADCAST 1 // 0X01
which might make it easier to understand