<s>
In	O
computer	O
hardware	O
,	O
a	O
word	B-Device
mark	I-Device
or	O
flag	O
is	O
a	O
bit	O
in	O
each	O
memory	O
location	O
on	O
some	O
variable	O
word	O
length	O
computers	O
(	O
e.g.	O
,	O
IBM	B-Device
1401	I-Device
,	O
1410	B-Device
,	O
1620	B-Device
)	O
used	O
to	O
mark	O
the	O
end	O
of	O
a	O
word	O
.	O
</s>
<s>
Sometimes	O
the	O
actual	O
bit	O
used	O
as	O
a	O
word	B-Device
mark	I-Device
on	O
a	O
given	O
machine	O
is	O
not	O
called	O
word	B-Device
mark	I-Device
,	O
but	O
has	O
a	O
different	O
name	O
(	O
e.g.	O
,	O
flag	O
on	O
the	O
IBM	B-Device
1620	I-Device
,	O
because	O
on	O
this	O
machine	O
it	O
is	O
multipurpose	O
)	O
.	O
</s>
<s>
The	O
term	O
word	B-Device
mark	I-Device
should	O
not	O
be	O
confused	O
with	O
group	O
mark	O
or	O
with	O
record	O
mark	O
,	O
which	O
are	O
distinct	O
characters	O
.	O
</s>
