Release/buyout clauses are becoming increasingly prevalent in football in recent times, especially as the business of the game burgeons.In Spain, a buyout clause, which is mandatory in a footballer's contract, has led to dramatic moments such as the one when PSG activated Neymar's gargantuan release clause of €222 million to make him the most expensive football player in the world.Recently, Lionel Messi's humongous release clause led to him staying back in Barcelona despite almost putting pen to paper on a deal with Manchester City. Messi's contract did have a special clause that could let him walk away for free at the end of every season, but the date for the same had passed.So what is a release clause in a football player's contract? Simply put, it is an amount stipulated in the player's contract that, if paid by another club, will automatically lead to the player being sold to that club. The release clause amount is usually higher than the market value of the football player and is aimed at deterring the player from moving on before his contract expires.Sometimes though, despite a huge release clause, a football player is sold without activating the same. The most famous case of this in recent times was that of Cristiano Ronaldo being sold by Real Madrid to Juventus. Ronaldo reportedly had a €1 billion release clause in his contract with the La Liga giants.10 highest release clauses in footballWith release clauses becoming more of a norm and already dominating the football market in Spain, we take a look at the ten highest release clauses right now. (All amounts are in GBP.)#T9 Gareth Bale - £423 millionGareth Bale.Yes, the football world now knows that Gareth Bale's torrid time in Madrid has come to an end for now after Tottenham finalised a season-long loan deal to bring him back to the North London club. Bale, whose contract with Real Madrid runs till 2022, comes in at tenth on this list because of his huge release clause.Bale, who fell out with Real Madrid coach Zinedine Zidane in recent times, has won every silverware possible for the La Liga giants and has contributed immensely to the club's success before running out of favour with the boss.HE’S ARRIVED 💉💉💉#GarethBale pic.twitter.com/Rvxq7yXdi0— Sam Chippeck (@SamChippeck) September 18, 2020#T9 Gerard Pique - £423 millionGerard Pique.It seems that Gerard Pique is staying on at Barcelona. This, despite the World Cup-winning central-defender offering to move away if the team felt a change was necessary following Barcelona's 2-8 drubbing at the hands of Bayern Munich in the Champions League quarter-final.Gerard Piqué: "I'm in pain. We all are. We can't compete like that. It's very, very tough to take. Nothing more is worth saying. The club needs changes. Not just the players, I don't want to point out anyone." pic.twitter.com/EkH00RszKw— Bayern & Germany (@iMiaSanMia) August 14, 2020Pique, 33, has won European and national honours multiple times for the club and has played for Barcelona more than 500 times. Like Bale, Pique's contract also runs till 2022 and his release clause is also of the same amount as that of the Welshman.Pique, unlike Bale, remains in his club's scheme of things as Barcelona try to rebuild under Ronald Koeman.