"wages" means basic wages and all other payments in cash payable to an employee for work done in respect of his contract of service but does not include --
(a) the value of any house accommodation or the supply of any food, fuel, light or water or medical attendance, or of any approved amenity or approved service;
(b) any contribution paid by the employer on his own account to any pension fund, provident fund, superannuation scheme, retrenchment, termination, lay-off or retirement scheme, thrift scheme or any other fund or scheme established for the benefit or welfare of the employee;
(c) any travelling allowance or the value of any travelling concession;
(d) any sum payable to the employee to defray special expenses entailed on him by the nature of his employment;
(e) any gratuity payable on discharge or retirement; or
(f) any annual bonus or any part of any annual bonus;
http://www.ilo.org/dyn/natlex/docs/WEBTEXT/48055/66265/E55mys01.htm#p1