<s>
Control-Y	B-Device
is	O
a	O
common	O
computer	O
command	O
.	O
</s>
<s>
It	O
is	O
generated	O
by	O
holding	O
and	O
pressing	O
the	O
key	O
on	O
most	O
computer	B-Device
keyboards	I-Device
.	O
</s>
<s>
In	O
most	O
Windows	O
applications	O
this	O
keyboard	B-Device
shortcut	O
functions	O
as	O
Redo	B-Application
,	O
reversing	O
a	O
previous	O
Undo	B-Application
.	O
</s>
<s>
In	O
some	O
programs	O
such	O
as	O
Microsoft	B-Application
Office	I-Application
it	O
repeats	O
the	O
previous	O
action	O
if	O
it	O
was	O
something	O
other	O
than	O
Undo	B-Application
.	O
</s>
<s>
Apple	B-Device
Macintosh	I-Device
systems	O
use	O
for	O
Redo	B-Application
.	O
</s>
<s>
In	O
general	O
a	O
shortcut	O
on	O
Macintosh	B-Device
using	O
matches	O
up	O
with	O
a	O
shortcut	O
on	O
Windows	O
using	O
,	O
this	O
is	O
one	O
of	O
the	O
most	O
noticeable	O
conflicts	O
.	O
</s>
<s>
Many	O
programs	O
(	O
on	O
all	O
systems	O
including	O
Linux	B-Application
)	O
support	O
both	O
and	O
for	O
Redo	B-Application
to	O
resolve	O
this	O
conflict	O
.	O
</s>
<s>
The	O
OpenVMS	B-Operating_System
operating	O
system	O
command-line	O
uses	O
as	O
its	O
"	O
abort	O
"	O
character	O
,	O
stronger	O
in	O
effect	O
than	O
the	O
ordinary	O
"	O
interrupt	O
"	O
character	O
.	O
</s>
<s>
deleted	O
the	O
current	O
line	O
in	O
the	O
WordStar	B-Application
word	O
processor	O
for	O
CP/M	B-Application
and	O
MS-DOS	B-Application
.	O
</s>
<s>
In	O
the	O
1980s	O
,	O
many	O
text	O
editors	O
and	O
word	O
processors	O
mimicked	O
the	O
WordStar	B-Application
command	O
set	O
,	O
making	O
a	O
common	O
synonym	O
for	O
"	O
delete	O
line.	O
"	O
</s>
<s>
In	O
emacs	B-Application
it	O
does	O
a	O
paste	O
action	O
(	O
known	O
as	O
"	O
yank	O
"	O
)	O
.	O
</s>
<s>
Emacs	B-Application
uses	O
for	O
Undo	B-Application
and	O
Redo	B-Application
.	O
</s>
<s>
In	O
vi	B-Application
and	O
vim	B-Application
it	O
scrolls	O
the	O
display	O
up	O
one	O
line	O
.	O
</s>
<s>
In	O
the	O
pico	B-Operating_System
and	O
nano	B-Application
text	I-Application
editors	I-Application
this	O
shortcut	O
scrolls	O
one	O
page	O
up	O
.	O
</s>
<s>
In	O
SAP	O
GUI	O
it	O
enters	O
block-select	O
mode	O
.	O
</s>
