1. A controller for a display screen, comprising: an input element for receiving character information from a user input interface; an output element for providing display information to the display screen; an electronic storage element for storing a symbol character set comprising a sequence of non-text symbol characters; and a processor element, operatively coupled to each of the input element, output element and electronic storage element, for generating display information comprising an address field with an address contained therein by (i) receiving a plurality of inputs for the address field from the input element; (ii) adding text characters to the address field of the display information corresponding to received inputs that are text character inputs; and (iii) detecting repetitive successive inputs of a predetermined delimiter, selecting a non-text symbol character from the symbol character set in dependence on a number of times the delimiter has been repetitively input without any intervening inputs, and adding the selected non-text symbol character to the address field of the display information when an input other than the delimiter is received.