<s>
Write	B-Device
once	I-Device
read	I-Device
many	I-Device
(	O
WORM	B-Device
)	O
describes	O
a	O
data	B-General_Concept
storage	I-General_Concept
device	I-General_Concept
in	O
which	O
information	O
,	O
once	O
written	O
,	O
cannot	O
be	O
modified	O
.	O
</s>
<s>
This	O
write	B-Device
protection	I-Device
affords	O
the	O
assurance	O
that	O
the	O
data	O
cannot	O
be	O
tampered	O
with	O
once	O
it	O
is	O
written	O
to	O
the	O
device	O
,	O
excluding	O
the	O
possibility	O
of	O
data	B-General_Concept
loss	I-General_Concept
from	O
human	O
error	O
,	O
computer	B-Error_Name
bugs	I-Error_Name
,	O
or	O
malware	O
.	O
</s>
<s>
On	O
ordinary	O
(	O
non-WORM	O
)	O
data	B-General_Concept
storage	I-General_Concept
devices	I-General_Concept
,	O
the	O
number	O
of	O
times	O
data	O
can	O
be	O
modified	O
is	O
limited	O
only	O
by	O
the	O
lifespan	O
of	O
the	O
device	O
,	O
as	O
modification	O
involves	O
physical	O
changes	O
that	O
may	O
cause	O
wear	O
to	O
the	O
device	O
.	O
</s>
<s>
WORM	B-Device
protects	O
the	O
important	O
files	B-Operating_System
by	O
keeping	O
them	O
safe	O
and	O
intact	O
.	O
</s>
<s>
This	O
way	O
,	O
the	O
WORM	B-Device
helps	O
to	O
preserve	O
the	O
authenticity	O
and	O
safety	O
of	O
recorded	O
data	O
.	O
</s>
<s>
WORM	B-Device
drives	I-Device
preceded	O
the	O
invention	O
of	O
the	O
CD-R	O
,	O
DVD-R	O
and	O
BD-R	B-Operating_System
.	O
An	O
example	O
was	O
the	O
IBM	O
3363	O
.	O
</s>
<s>
These	O
drives	O
typically	O
used	O
a	O
disk	O
in	O
a	O
cartridge	O
,	O
with	O
an	O
ablative	B-Algorithm
optical	O
layer	O
that	O
could	O
be	O
written	O
to	O
only	O
once	O
,	O
and	O
were	O
often	O
used	O
in	O
places	O
like	O
libraries	O
that	O
needed	O
to	O
store	O
large	O
amounts	O
of	O
data	O
.	O
</s>
<s>
Punched	B-Architecture
cards	I-Architecture
and	O
paper	O
tape	O
are	O
obsolete	O
WORM	B-Device
media	O
.	O
</s>
<s>
Read-only	B-Device
memory	I-Device
(	O
ROM	B-Device
)	O
is	O
also	O
a	O
WORM	B-Device
medium	O
.	O
</s>
<s>
Such	O
memory	O
may	O
contain	O
the	O
instructions	O
to	O
a	O
computer	O
to	O
read	O
the	O
operating	B-General_Concept
system	I-General_Concept
from	O
another	O
storage	O
device	O
such	O
as	O
a	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
The	O
non-technical	O
end-user	O
,	O
however	O
,	O
cannot	O
write	O
the	O
ROM	B-Device
even	O
once	O
but	O
considers	O
it	O
part	O
of	O
the	O
unchangeable	O
computing	B-Device
platform	I-Device
.	O
</s>
<s>
WORM	B-Device
was	O
utilized	O
for	O
Broker-dealer	O
records	O
within	O
the	O
Financial	O
Industry	O
Regulatory	O
Authority	O
and	O
the	O
U.S.	O
Securities	O
and	O
Exchange	O
Commission	O
.	O
</s>
<s>
The	O
CD-R	O
,	O
DVD-R	O
and	O
BD-R	B-Operating_System
optical	B-Device
discs	I-Device
for	O
computers	O
are	O
common	O
WORM	B-Device
devices	O
.	O
</s>
<s>
Through	O
packet	B-Device
writing	I-Device
,	O
which	O
uses	O
the	O
Universal	O
Disk	O
Format	O
(	O
UDF	O
)	O
file	B-Application
system	I-Application
,	O
these	O
discs	O
often	O
use	O
a	O
file	B-Application
system	I-Application
that	O
permits	O
additional	O
files	B-Operating_System
,	O
and	O
even	O
revised	O
versions	O
of	O
a	O
file	O
by	O
the	O
same	O
name	O
,	O
to	O
be	O
recorded	O
in	O
a	O
different	O
region	O
of	O
the	O
disc	O
.	O
</s>
<s>
The	O
SD	B-Device
card	I-Device
and	O
microSD	O
card	O
spec	O
allows	O
for	O
multiple	O
forms	O
of	O
write-protection	B-Device
.	O
</s>
<s>
The	O
most	O
common	O
form	O
,	O
only	O
available	O
when	O
using	O
a	O
full-size	O
SD	B-Device
card	I-Device
,	O
provides	O
a	O
physical	O
write	B-Device
protection	I-Device
switch	O
which	O
allows	O
the	O
user	O
to	O
advise	O
the	O
host	O
card	O
reader	O
to	O
disallow	O
write	O
access	O
.	O
</s>
<s>
This	O
does	O
not	O
protect	O
the	O
data	O
on	O
the	O
card	O
if	O
the	O
card	O
reader	O
hardware	O
is	O
not	O
built	O
to	O
respect	O
the	O
write	B-Device
protection	I-Device
switch	O
.	O
</s>
<s>
Multiple	O
vendors	O
beginning	O
in	O
the	O
early	O
2000s	O
developed	O
Magnetic	O
WORM	B-Device
devices	O
.	O
</s>
<s>
In	O
2013	O
,	O
GreenTec-USA	O
,	O
Inc	O
.	O
developed	O
WORM	B-Device
hard	B-Device
disk	I-Device
drives	I-Device
in	O
capacities	O
of	O
3TB	O
and	O
greater	O
.	O
</s>
<s>
In	O
recent	O
years	O
there	O
has	O
been	O
a	O
renewed	O
interest	O
in	O
WORM	B-Device
based	O
on	O
organic	O
components	O
,	O
such	O
as	O
PEDOT:PSS	B-Algorithm
or	O
other	O
polymers	O
such	O
as	O
PVK	O
or	O
PCz	O
.	O
</s>
<s>
Organic	O
WORM	B-Device
devices	O
,	O
considered	O
organic	O
memory	O
,	O
could	O
be	O
used	O
as	O
memory	O
elements	O
for	O
low-power	O
RFID	B-Application
tags	I-Application
.	O
</s>
