<s>
In	O
computing	O
,	O
caret	B-Application
navigation	I-Application
(	O
or	O
caret	B-Application
browsing	I-Application
)	O
is	O
a	O
kind	O
of	O
keyboard	O
navigation	O
where	O
a	O
caret	B-Application
(	O
also	O
known	O
as	O
a	O
‘	O
text	O
cursor’	O
,	O
‘	O
text	O
insertion	O
cursor’	O
,	O
or	O
‘	O
text	B-General_Concept
selection	I-General_Concept
cursor’	O
)	O
is	O
used	O
to	O
navigate	O
within	O
a	O
text	O
document	O
.	O
</s>
<s>
It	O
is	O
a	O
fundamental	O
feature	O
for	O
applications	O
that	O
deal	O
with	O
text	O
,	O
for	O
example	O
text	B-Application
editors	I-Application
(	O
e.g.	O
,	O
Notepad	B-Application
,	O
Emacs	B-Application
and	O
Vim	B-Application
)	O
,	O
word	B-General_Concept
processors	I-General_Concept
(	O
e.g.	O
,	O
Microsoft	B-Application
Word	I-Application
,	O
WordPerfect	B-Application
and	O
WordStar	B-Application
)	O
,	O
document	B-Application
viewer	I-Application
(	O
e.g.	O
,	O
Atril	O
)	O
,	O
desktop	O
publishing	O
programs	O
(	O
e.g.	O
,	O
PageMaker	B-Operating_System
,	O
Microsoft	O
Publisher	O
)	O
,	O
and	O
spreadsheets	O
(	O
e.g.	O
,	O
Excel	B-Application
,	O
Lotus	B-Application
1-2-3	I-Application
)	O
.	O
</s>
<s>
This	O
kind	O
of	O
navigation	O
is	O
also	O
supported	O
by	O
the	O
major	O
web	B-Application
browsers	I-Application
,	O
namely	O
Mozilla	B-Application
Firefox	I-Application
,	O
Chromium	B-Language
(	O
with	O
derivatives	O
of	O
said	O
browsers	B-Application
retaining	O
this	O
feature	O
)	O
and	O
Internet	B-Application
Explorer	I-Application
.	O
</s>
<s>
where	O
it	O
is	O
referred	O
to	O
as	O
‘	O
caret	O
browsing’	O
;	O
it	O
is	O
typically	O
accessed	O
with	O
the	O
function	B-Application
key	I-Application
f7	O
.	O
</s>
<s>
In	O
this	O
text	O
navigation	O
mode	O
the	O
‘	O
cursor’	O
,	O
often	O
depicted	O
as	O
a	O
blinking	O
vertical	O
line	O
,	O
appears	O
within	O
the	O
text	O
on-screen	O
.	O
</s>
<s>
The	O
user	O
can	O
then	O
navigate	O
throughout	O
the	O
text	O
by	O
using	O
the	O
arrow	O
navigation	O
keys	O
to	O
cause	O
the	O
cursor	B-Application
to	O
move	O
;	O
typically	O
changing	O
the	O
cursor	B-Application
's	O
location	O
in	O
increments	O
of	O
character	O
position	O
horizontally	O
and	O
of	O
text	B-General_Concept
line	I-General_Concept
vertically	O
.	O
</s>
<s>
Once	O
the	O
cursor	B-Application
has	O
been	O
positioned	O
as	O
desired	O
,	O
any	O
text	O
typed	O
will	O
appear	O
at	O
the	O
location	O
of	O
the	O
cursor	B-Application
,	O
either	O
inserting	O
the	O
text	O
and	O
pushing	O
any	O
subsequent	O
text	O
further	O
downwards	O
,	O
or	O
overwriting	O
any	O
existing	O
text	O
(	O
a	O
mode	O
of	O
operation	O
typically	O
toggled	O
by	O
the	O
Insert	B-Device
Key	I-Device
on	O
most	O
computer	O
keyboards/systems	O
)	O
.	O
</s>
<s>
selecting	B-General_Concept
a	O
block	O
of	O
text	O
to	O
e.g.	O
</s>
<s>
Caret	B-Application
navigation	I-Application
usually	O
also	O
incorporates	O
a	O
form	O
of	O
viewport	O
scrolling	O
control	O
where	O
the	O
caret	B-Application
moves	O
freely	O
within	O
certain	O
margins	O
of	O
a	O
static	O
display	O
but	O
triggers	O
a	O
scrolling	O
event	O
upon	O
reaching	O
one	O
of	O
the	O
margins	O
(	O
either	O
the	O
edge	O
of	O
the	O
screen/window/text	O
field	O
or	O
a	O
point	O
a	O
certain	O
number	O
of	O
lines/characters	O
within	O
said	O
edge	O
)	O
.	O
</s>
<s>
The	O
view	O
within	O
a	O
WYSIWYG	B-Application
word	B-General_Concept
processor	I-General_Concept
,	O
for	O
example	O
,	O
may	O
scroll	O
the	O
whole	O
viewport	O
a	O
certain	O
amount	O
down	O
the	O
page	O
as	O
the	O
caret	B-Application
nears	O
the	O
lower	O
edge	O
of	O
the	O
edit	O
window	O
.	O
</s>
<s>
A	O
spreadsheet	O
character-based	B-Application
word	B-General_Concept
processor	I-General_Concept
on	O
a	O
low-resolution	O
screen	O
may	O
similarly	O
scroll	O
in	O
all	O
directions	O
,	O
character-by-character	O
or	O
line-by-line	O
,	O
maintaining	O
a	O
small	O
margin	O
which	O
the	O
caret	B-Application
never	O
enters	O
in	O
order	O
to	O
show	O
the	O
user	O
what	O
text	O
or	O
cells	O
lie	O
directly	O
‘	O
ahead’	O
of	O
or	O
‘	O
behind’	O
the	O
edit	O
point	O
and	O
prevent	O
them	O
from	O
‘	O
working	O
blind’	O
.	O
</s>
<s>
A	O
plain	O
text	O
text	O
entry	O
form	O
,	O
by	O
contrast	O
,	O
may	O
use	O
a	O
simpler	O
method	O
,	O
setting	O
a	O
fixed	O
and	O
arbitrary	O
display	O
width	O
within	O
which	O
the	O
caret	B-Application
always	O
‘	O
wraps	O
around’	O
,	O
only	O
scrolling	O
up	O
or	O
down	O
a	O
line	O
as	O
the	O
caret	B-Application
reaches	O
the	O
wrap	O
point	O
at	O
the	O
start/end	O
of	O
the	O
current	O
first/last	O
line	O
,	O
in	O
order	O
to	O
keep	O
the	O
edit	O
point	O
in	O
view	O
as	O
it	O
moves	O
to	O
the	O
previous/next	O
line	B-General_Concept
of	I-General_Concept
text	I-General_Concept
.	O
</s>
<s>
Another	O
alternate	O
form	O
of	O
control	O
is	O
used	O
in	O
some	O
spreadsheets	O
when	O
the	O
Scroll	B-Device
Lock	I-Device
key	I-Device
is	O
activated	O
.	O
</s>
<s>
In	O
this	O
case	O
the	O
caret	B-Application
is	O
locked	O
to	O
the	O
centre	O
of	O
the	O
screen	O
and	O
the	O
cursor	B-Application
keys	O
instead	O
move	O
the	O
worksheet	O
itself	O
‘	O
underneath’	O
the	O
static	O
caret	B-Application
,	O
instead	O
of	O
the	O
caret	B-Application
moving	O
‘	O
over’	O
the	O
sheet	O
.	O
</s>
<s>
The	O
margins	O
that	O
trigger	O
a	O
scrolling	O
action	O
are	O
effectively	O
increased	O
to	O
their	O
maximum	O
possible	O
size	O
(	O
vs	O
the	O
minimum	O
possible	O
with	O
the	O
web	O
edit	O
box	O
)	O
,	O
causing	O
the	O
caret	B-Application
to	O
be	O
re-centered	O
any	O
time	O
it	O
attempts	O
to	O
move	O
.	O
</s>
