The competition is open to children of 12 years old or below ( i . e . born in or after 1989 ) . participants are required to send in their self - designed envelopes with the coloured children stamps by 8 december 2001 比赛欢迎十二岁或以下（即一九八九年或以前出生）的儿童参加，参赛者须在十二月八日前将自行设计的信封，连同填上颜色的邮票交回。
