Goal-line technology has been approved in principle by the football’s lawmakers and could be used for the first time at Fifa’s Club World Cup finals in Japan at the end of the year.The eight-man International Football Association Board said that the technologies of two companies, Hawk-Eye from Britain and GoalRef, a German-Danish company, would be subject to further tests until a final decision was taken at a special IFAB meeting in Kiev on July 2.IFAB, which comprises four representatives from the world governing body Fifa and four from the British associations, also agreed in principle to overturn the decision they took in 2007 and will now allow Islamic women footballers to wear a hijab, or headscarf, when they play.The hijab decision, taken after a presentation to the Board by Fifa executive committee member Prince Ali Bin Al Hussein of Jordan, was agreed by all eight members and will also be subject to further testing with a view to a final decision on July 2."I am deeply grateful that the proposal to allow women to wear the headscarf was unanimously endorsed by all members of IFAB,” Prince Ali said.In other decisions, a proposal from Fifa to allow a fourth substitute in extra time in Cup matches was withdrawn while further discussions will be taken regarding the "triple punishment” sanction when a player concedes a penalty, is sent off and faces a suspension for preventing a goal-scoring opportunity.IFAB also approved the use of "vanishing spray”, the temporary marker sprayed on to the pitch by the referee so defenders stand 10 yards (9.15 metres) from free-kicks, can also be used in matches, It also allowed rolling substitutes in amateur and veterans matches.The issue of goal-line technology has been on and off IFAB’s agenda over the last decade, but Fifa president Sepp Blatter, once a staunch opponent, changed his mind after Frank Lampard’s infamous phantom goal for England against Germany in the 2010 World Cup finals was disallowed when it was clearly over the line.Blatter said before the meeting he "would rather die” than witness another blunder like that in a future World Cup and with his support, the introduction of the system became more likely.Jerome Valcke, Fifa’s general secretary, added: "If it is approved on July 2, then there is nothing to stop it being used on July 3, but in reality, the first Fifa competition it might be used at would be the Club World Cup finals in Japan in December. It should also be used at the Confederations Cup in Brazil next year before the World Cup in 2014.”The Confederations Cup is used as a rehearsal for the finals and between four and six World Cup stadiums should feature in that tournament.