<s>
Janus	B-Device
was	O
the	O
codename	O
of	O
a	O
version	O
of	O
Windows	O
Media	O
DRM	O
primarily	O
for	O
portable	O
devices	O
,	O
whose	O
marketing	O
name	O
was	O
Windows	O
Media	O
DRM	O
for	O
Portable	O
Devices	O
(	O
or	O
in	O
short	O
form	O
WMDRM-PD	B-Device
)	O
.	O
</s>
<s>
Napster	O
To	O
Go	O
was	O
the	O
first	O
online	O
music	O
store	O
to	O
require	O
the	O
Janus	B-Device
technology	O
.	O
</s>
<s>
Supporting	O
Janus	B-Device
often	O
implies	O
that	O
the	O
device	O
also	O
makes	O
use	O
of	O
Media	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
(	O
MTP	O
)	O
.	O
</s>
<s>
Janus	B-Device
initially	O
required	O
supporting	O
devices	O
to	O
not	O
support	O
non-Microsoft	O
audio	O
formats	O
such	O
as	O
Ogg	B-Algorithm
Vorbis	I-Algorithm
,	O
but	O
this	O
requirement	O
was	O
later	O
removed	O
.	O
</s>
<s>
To	O
support	O
Janus	B-Device
,	O
devices	O
must	O
support	O
:	O
</s>
