The flag may also be flown at half-staff when the Central People's Government advises the Chief Executive to do so, or when the Chief Executive considers it appropriate to do so, on occurrences of unfortunate events causing especially serious casualties, or when serious natural calamities have caused heavy casualties. When raising a flag to be flown at half-staff, it should first be raised to the top of the pole and then lowered to a point where the distance between the top of the flag and the top of the pole is one third of the length of the pole. When lowering the flag from half-staff, it should first be raised to the peak of the pole before it is lowered.