A FEW weeks ago a reader phoned me up with a query about the disciplinary cards referees use in football.

Most people probably know these were introduced after the 1966 World Cup at Wembley.

English referee, Ken Aston, had difficulty in making an Argentinian player, understand that he had to leave the field after being sent off by the German referee.

On his way home Aston stopped at traffic lights, which gave him the idea for red and yellow cards.

My caller however, said his wife had told him there were now green cards as well.

I told him quite confidently that his wife had obviously got it wrong.

I have refereed some small-aside tournaments, where blue cards are used to indicate a player has been sent to the sin bin, but in regular 11-a-side football the only cards are red and yellow.

Since then, however, I have had to contact my caller to give my apologies to his wife, because she is obviously better informed than I was.

So where does the green card come from, where is it used and what does it signify?

First a little history. In 1886 the home nations, England, Scotland, Wales and Ireland wanted to play international matches against each other, but all had different rules.

So they formed the International FA Board and gave it sole jurisdiction over writing the laws, which they would all obey.

FIFA joined the Board in 1916 so all countries, who affiliate with FIFA, must abide by the same laws.

It is not always realised there are a number of countries not affiliated to FIFA.

These are small countries such as Tuvalu, members of the Confederation of Independent FAs, who are free to fix their own Laws of the Game.

One such variation they have recently introduced is the green card.

I’m not sure what offences it covers, but when a player is shown a green card, he must leave the field of play, but can be replaced.

I think it’s unlikely to be adopted by the IFAB.