A method of generating an association between an object and a sticker on a surface, the sticker having disposed therein or thereon coded data at least partially indicative of a sticker identity, the method including, in a computer system: receiving indicating data from a sensing device, the indicating data being at least partially indicative of the identity of the sticker, the sensing device being responsive to sensing at least some of the coded data to generate the indicating data; identifying, using the indicating data, the identity of the sticker on the surface; and, generating an association based at least partially on the sticker identity and an object.