The congress has endorsed Sepp Blatter's 'six-plus-five' principle

Fifa has signed the new World Anti-Doping code after agreeing a revised set of rules with the World Anti-Doping Agency (Wada).

Football's governing body signed after Wada agreed to remove the uniform two-year ban imposed on drug cheats.

Fifa had preferred to treat offences on a case-by-case basis rather than implementing the mandatory suspension.

The new code, which comes into force on 1 January 2009, will allow greater flexibility in the sanctions imposed.

Fifa had agreed to sign the accord last year after Wada proposed a revised set of rules, which were endorsed by sporting bodies at a doping conference in Spain.

There will be more flexibility in the punishment handed out to athletes who can prove they did not deliberately take performance-enhancing drugs.

The "whereabouts" rule, which requires athletes to inform anti-doping authorities of their location in case of testing, will also be revised.

Wada boss John Fahey believes getting backing from Fifa, which was one of the last Olympic sport federations to accept the Wada code, is a major breakthrough.

"The commitment of Fifa has been strong and I believe will be even stronger in the days ahead," Fahey told the congress.

"Football is a giant in the universe of team sport and your example is of paramount importance.

"Your support will be noticed and followed by other team sports around the world."

606: DEBATE Blatter has an unwinnable fight on his hands BBC Sport's Phil McNulty

Blatter wants to restrict the number of foreign players in teams by the start in the 2010/11 season, with a minimum of four home-grown players.

He added he expects it to grow to six, with a maximum of five foreigners, by 2012/13 - and claims the plan has the backing of key European delegates.