<s>
An	O
unreferenced	B-General_Concept
variable	I-General_Concept
in	O
the	O
source	O
code	O
of	O
a	O
computer	B-Application
program	I-Application
is	O
a	O
variable	O
that	O
is	O
defined	O
but	O
which	O
is	O
never	O
used	O
.	O
</s>
<s>
Many	O
compilers	B-Language
detect	O
such	O
variables	O
and	O
do	O
not	O
allocate	O
storage	O
for	O
them	O
(	O
i.e.	O
,	O
"	O
optimize	O
away	O
"	O
their	O
storage	O
)	O
,	O
generally	O
also	O
issuing	O
a	O
warning	O
as	O
they	O
do	O
.	O
</s>
<s>
Some	O
coding	B-Language
guideline	I-Language
documents	O
consider	O
an	O
unreferenced	B-General_Concept
variable	I-General_Concept
to	O
be	O
a	O
symptom	O
of	O
a	O
potential	O
coding	O
fault	O
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
unreferenced	B-General_Concept
variables	I-General_Concept
can	O
be	O
used	O
as	O
temporary	O
placeholders	O
to	O
indicate	O
further	O
expected	O
future	O
developments	O
in	O
the	O
code	O
.	O
</s>
<s>
C	B-Language
:	O
</s>
<s>
In	O
this	O
example	O
,	O
j	O
is	O
an	O
unreferenced	B-General_Concept
variable	I-General_Concept
.	O
</s>
