Fields for Edge-Punched Filing Cards.
New fields have been devised, for a double-row edge-punched card, which require only three edge holes per field in place of the customary four. The new fields record every digit and no digit appears more than once. Any letter of the alphabet can be readily punched into a single field. Sorting of the new fields (compared to sorting of existing fields) requires fewer needle passes for both alphabetical and numerical searching, if a single search is made; this does not apply in arranging the cards in sequence.
Newcombe
A G
AG