A method of conveying information between a wireless communication device (13a) and a computer (15) providing a messaging service comprising sending a message from the wireless communication device (13a) to said computer (15), the message including an address for the computer (15), and receiving the communication at the computer (15). The address is formed by combining an Access Code (AC) uniquely identifying the computer and a Unique Identification Code (UIC) signifying; (i) a prescribed action to be performed by the computer (15); and (ii) an entity that is the subject of the prescribed action. At least one character of the address is common to both the Access Code and the Unique identification Code and the address is arranged such that said at least one common character is unified within the address such that the number of characters in the address string is less than the total number of characters in the Access Code and the Unique Identification Code.