lace card: n. obs. A punched card with all holes punched
(also called a `whoopee card' or `ventilator card'). Card readers
tended to jam when they got to one of these, as the resulting card
had too little structural strength to avoid buckling inside the
mechanism. Card punches could also jam trying to produce these
things owing to power-supply problems. When some practical joker
fed a lace card through the reader, you needed to clear the jam with
a `card knife' -- which you used on the joker first.
![[prev]](../gif/left.gif){kind=small}
![[up]](../gif/up.gif){kind=small}
![[next]](../gif/right.gif){kind=small}