THE USE OF NOTCHES IN CARDS AS A MEANS OF SIGNALLING INFORMATION Available to Purchase

It has often seemed to the writer that more use might be made of the upper edges of catalogue cards for signalling information about the works covered. Together these edges form a nearly plane surface, yet this is unused. Coloured signals have been used, it is true, but they interlock, slip, and pad out the card record; the last fault alone debars them from use in a file of any size.