Probably the case where he get an automatic extension if he plays a minimum amount of games. <edit> As already written above...
Gary Taylor Fletcher had that clause hence why he got another year for this season. Apart from coming on against Chelsea and looking 5 stone over weight and did do anything so apart from financially which is probably what he wanted he was no better off signing a new deal
Ayew is apparently on the verge of joining Swansea... shame Julian Dicks has retired... childish I know but in a parallel universe a commentary might go "Dicks, Fuchs, Fanni .... MESSI!!"...