<s>
DVD-R	B-Device
DL	I-Device
(	O
DL	O
stands	O
for	O
Dual	O
Layer	O
)	O
,	O
also	O
called	O
DVD-R9	B-Device
,	O
is	O
a	O
derivative	O
of	O
the	O
DVD-R	O
format	O
standard	O
.	O
</s>
<s>
DVD-R	B-Device
DL	I-Device
discs	O
hold	O
8.5	O
GB	O
by	O
utilizing	O
two	O
recordable	O
dye	O
layers	O
,	O
each	O
capable	O
of	O
storing	O
a	O
little	O
less	O
than	O
the	O
4.7	O
gigabyte	O
(	O
GB	O
)	O
of	O
a	O
single	O
layer	O
disc	O
,	O
almost	O
doubling	O
the	O
total	O
disc	O
capacity	O
.	O
</s>
<s>
Discs	O
can	O
be	O
read	O
in	O
many	O
DVD	O
devices	O
(	O
older	O
units	O
are	O
less	O
compatible	O
)	O
and	O
can	O
only	O
be	O
written	O
using	O
DVD-R	B-Device
DL	I-Device
compatible	O
recorders	O
.	O
</s>
<s>
It	O
is	O
part	O
of	O
optical	B-Device
disc	I-Device
recording	I-Device
technologies	I-Device
for	O
digital	O
recording	O
to	O
optical	B-Device
disc	I-Device
.	O
</s>
<s>
DVD-R	B-Device
DL	I-Device
has	O
compatibility	O
issues	O
with	O
legacy	O
DVD-ROM	O
drives	O
known	O
as	O
pickup	O
head	O
overrun	B-General_Concept
.	O
</s>
<s>
DVD-R	B-Device
DL	I-Device
media	O
has	O
been	O
discontinued	O
by	O
most	O
manufacturers	O
.	O
</s>
<s>
DVD-R	B-Device
DL	I-Device
was	O
developed	O
for	O
the	O
DVD	O
Forum	O
by	O
Pioneer	O
Corporation	O
,	O
DVD+R	O
DL	O
(	O
formally	O
known	O
as	O
Double	O
Layer	O
)	O
was	O
developed	O
for	O
the	O
DVD+RW	O
Alliance	O
by	O
Philips	O
and	O
Mitsubishi	O
Kagaku	O
Media	O
(	O
MKM	O
)	O
.	O
</s>
<s>
The	O
layer	O
change	O
can	O
exhibit	O
a	O
noticeable	O
pause	O
in	O
some	O
DVD	B-Device
players	I-Device
,	O
up	O
to	O
several	O
seconds	O
.	O
</s>
<s>
Detail	O
differences	O
in	O
formatting	O
and	O
file	O
structure	O
mean	O
the	O
"	O
usable	O
"	O
data	O
area	O
capacity	O
does	O
not	O
change	O
by	O
exactly	O
this	O
much	O
,	O
but	O
for	O
all	O
intents	O
a	O
DVD-R	B-Device
DL	I-Device
has	O
effectively	O
20/11ths	O
the	O
capacity	O
of	O
a	O
DVD-R	O
SL	O
,	O
and	O
the	O
same	O
holds	O
for	O
+R	O
,	O
commercially	O
pressed	O
,	O
and	O
8cm	O
discs	O
.	O
</s>
<s>
DVD	O
recordable	O
discs	O
supporting	O
this	O
technology	O
are	O
backward	O
compatible	O
with	O
some	O
existing	O
DVD	B-Device
players	I-Device
and	O
DVD-ROM	O
drives	O
.	O
</s>
