<s>
Index	B-Device
mark	I-Device
has	O
multiple	O
meanings	O
.	O
</s>
<s>
In	O
computing	O
,	O
an	O
index	B-Device
mark	I-Device
or	O
index	B-Device
track	I-Device
is	O
a	O
physical	O
impression	O
made	O
on	O
a	O
hard	B-Device
disk	I-Device
drive	I-Device
.	O
</s>
<s>
Its	O
purpose	O
is	O
to	O
indicate	O
the	O
starting	O
point	O
for	O
each	O
track	B-Device
on	O
the	O
hard	B-Device
disk	I-Device
drive	I-Device
.	O
</s>
<s>
Usually	O
,	O
an	O
index	B-Device
mark	I-Device
takes	O
the	O
form	O
of	O
a	O
hole	O
,	O
gap	O
,	O
or	O
magnetic	O
strip	O
.	O
</s>
<s>
It	O
also	O
allows	O
a	O
hard	B-Device
disk	I-Device
drive	I-Device
head	O
to	O
quickly	O
move	O
to	O
various	O
spots	O
on	O
the	O
drive	O
.	O
</s>
<s>
In	O
electronics	O
components	O
,	O
an	O
index	B-Device
mark	I-Device
is	O
a	O
reference	O
symbol	O
printed	O
on	O
or	O
molded	O
into	O
the	O
casing	O
of	O
a	O
device	O
or	O
circuit	O
board	O
,	O
to	O
indicate	O
the	O
location	O
of	O
"	O
Pin	O
1	O
"	O
.	O
</s>
<s>
Another	O
kind	O
of	O
index	B-Device
mark	I-Device
is	O
a	O
component	O
of	O
the	O
registration	O
system	O
for	O
road	O
vehicles	O
in	O
the	O
United	O
Kingdom	O
.	O
</s>
