Abstract: A low cost, self locating auxiliary keyboard assembly is disclosed for changing the key configuration and classification of the keyboard of a data terminal device, the assembly including a cover member having a plurality of apertures which overlie associated control keys on the keyboard of the data terminal device. A classification indicia card having a plurality of predetermined positioned apertures is placed on the cover member, the apertures in the indicia card overlying certain of the apertures in the cover member to allow a removable auxiliary key member to be inserted within the aligned apertures of both the indicia card and the cover member to engage the top portion of the associated control key on the keyboard of the data terminal device for operation thereby.