<s>
The	O
gecos	B-Operating_System
field	I-Operating_System
,	O
or	O
GECOS	B-Operating_System
field	I-Operating_System
is	O
a	O
field	O
in	O
each	O
record	O
in	O
the	O
/etc/passwd	B-Protocol
file	O
on	O
Unix	B-Application
and	O
similar	O
operating	B-General_Concept
systems	I-General_Concept
.	O
</s>
<s>
On	O
UNIX	B-Application
,	O
it	O
is	O
the	O
5th	O
of	O
7	O
fields	O
in	O
a	O
record	O
.	O
</s>
<s>
The	O
typical	O
format	O
for	O
the	O
GECOS	B-Operating_System
field	I-Operating_System
is	O
a	O
comma-delimited	O
list	O
with	O
this	O
order	O
:	O
</s>
<s>
Any	O
other	O
contact	O
information	O
(	O
pager	B-Application
number	O
,	O
fax	O
,	O
external	O
e-mail	O
address	O
,	O
etc	O
.	O
)	O
</s>
<s>
In	O
most	O
UNIX	B-Application
systems	I-Application
non-root	O
users	O
can	O
change	O
their	O
own	O
information	O
using	O
the	O
chfn	O
or	O
chsh	O
command	O
.	O
</s>
<s>
Some	O
early	O
Unix	B-Application
systems	I-Application
at	O
Bell	O
Labs	O
used	O
GECOS	B-Application
machines	O
for	O
print	O
spooling	O
and	O
various	O
other	O
services	O
,	O
so	O
this	O
field	O
was	O
added	O
to	O
carry	O
information	O
on	O
a	O
user	O
's	O
GECOS	B-Application
identity	O
.	O
</s>
<s>
On	O
Internet	B-Protocol
Relay	I-Protocol
Chat	I-Protocol
(	O
IRC	B-Protocol
)	O
,	O
the	O
real	O
name	O
field	O
is	O
sometimes	O
referred	O
to	O
as	O
the	O
gecos	B-Operating_System
field	I-Operating_System
.	O
</s>
<s>
IRC	B-Protocol
clients	O
are	O
required	O
to	O
supply	O
this	O
field	O
when	O
connecting	O
.	O
</s>
<s>
Hexchat	B-Protocol
,	O
an	O
X-Chat	B-Protocol
fork	O
,	O
defaults	O
to	O
'	O
realname	O
 '	O
,	O
TalkSoup.app	O
on	O
GNUstep	B-Application
defaults	O
to	O
'	O
John	O
Doe	O
 '	O
,	O
and	O
irssi	B-Protocol
reads	O
the	O
operating	B-General_Concept
system	I-General_Concept
user	O
's	O
full	O
name	O
,	O
replacing	O
it	O
with	O
'	O
unknown	O
 '	O
if	O
not	O
defined	O
.	O
</s>
<s>
Some	O
IRC	B-Protocol
clients	O
use	O
this	O
field	O
for	O
advertising	O
;	O
for	O
example	O
,	O
ZNC	B-Application
defaulted	O
to	O
"	O
Got	O
ZNC	B-Application
?	O
</s>
