<s>
A	O
lace	B-Device
card	I-Device
is	O
a	O
punched	B-Architecture
card	I-Architecture
with	O
all	O
holes	O
punched	O
(	O
also	O
called	O
a	O
whoopee	B-Device
card	I-Device
,	O
ventilator	B-Device
card	I-Device
,	O
flyswatter	B-Device
card	I-Device
,	O
or	O
IBM	B-Device
doily	I-Device
)	O
.	O
</s>
<s>
They	O
were	O
mainly	O
used	O
as	O
practical	O
jokes	O
to	O
cause	O
disruption	O
in	O
card	B-Device
readers	I-Device
.	O
</s>
<s>
Card	B-Device
readers	I-Device
tended	O
to	O
jam	O
when	O
a	O
lace	B-Device
card	I-Device
was	O
inserted	O
,	O
as	O
the	O
resulting	O
card	O
had	O
too	O
little	O
structural	O
strength	O
to	O
avoid	O
buckling	O
inside	O
the	O
mechanism	O
.	O
</s>
<s>
Card	B-Device
punches	I-Device
could	O
also	O
jam	O
trying	O
to	O
produce	O
cards	O
with	O
all	O
holes	O
punched	O
,	O
owing	O
to	O
power-supply	O
problems	O
.	O
</s>
<s>
When	O
a	O
lace	B-Device
card	I-Device
was	O
fed	O
through	O
the	O
reader	O
,	O
a	O
card	O
knife	O
or	O
card	O
saw	O
(	O
a	O
flat	O
tool	O
used	O
with	O
punched	B-Device
card	I-Device
readers	I-Device
and	O
card	B-Device
punches	I-Device
)	O
was	O
needed	O
to	O
clear	O
the	O
jam	O
.	O
</s>
