With prickly regional, political and economic issues sure to trigger degrees of irritation at the Asia-Pacific Economic Co-operation summit in Yokohama, Japan, the leaders of the 21 nations can be forgiven for sighs of relief at being spared one indignity. The Japanese hosts have decided that instead of requiring presidents, prime ministers and other heads of state to each wrestle with a kimono for the final group photograph on Saturday, the emphasis should be on 'smart casual'. The hosts have decided to dispense with one of the more peculiar features of Apec summits - a 'family photo' in which leaders don traditional local garb. The Japanese ruling means open jackets will be the order of the day, and ties will be optional. And it does not hurt that the message the leaders will be sending out will be one of serious, hard work instead of frivolity. 'Regardless of their attire, we are very serious about attaining concrete progress at this Apec meeting,' Satoru Sato, a spokesman for the Japanese Ministry of Foreign Affairs, said. The Apec tradition of unusual outfits started when then US president Bill Clinton gave all his guests bomber jackets at the Blake Island meeting in Washington state in 1993. Since then, heads of state have posed in ponchos in Chile in 2004, worn Javan batik shirts for the Indonesian meeting in 1994 and the loose-fitting ao dai silk tunics in Vietnam in 2006. There were satin embroidered jackets in Shanghai in 2001 and outback-style coats in Sydney in 2007. The photos are popular with the media and the 'silly shirts' pictures invariably make the newspapers every year, while issues of substance are sometimes relegated to the background. But not this year. Instead, the 'smart casual' group photo opportunity will be staged, sandwiched between a performance of traditional kabuki theatre and an official dinner to be hosted by Japanese Prime Minister Naoto Kan. 'Japan hosted the Apec meeting in Osaka in 1985 and on that occasion we had the same policy of inviting the leaders of the nations that were represented to wear 'smart casual' dress instead of requiring them to wear traditional Japanese clothing or special attire,' Sato said.