<s>
Binary	B-General_Concept
Ordered	I-General_Concept
Compression	I-General_Concept
for	I-General_Concept
Unicode	I-General_Concept
(	O
BOCU	B-General_Concept
)	O
is	O
a	O
MIME	B-Protocol
compatible	O
Unicode	O
compression	O
scheme	O
.	O
</s>
<s>
BOCU-1	B-General_Concept
combines	O
the	O
wide	O
applicability	O
of	O
UTF-8	O
with	O
the	O
compactness	O
of	O
Standard	O
Compression	O
Scheme	O
for	O
Unicode	O
(	O
SCSU	O
)	O
.	O
</s>
<s>
This	O
Unicode	O
encoding	B-General_Concept
is	O
designed	O
to	O
be	O
useful	O
for	O
compressing	O
short	O
strings	O
,	O
and	O
maintains	O
code	O
point	O
order	O
.	O
</s>
<s>
BOCU-1	B-General_Concept
is	O
specified	O
in	O
a	O
Unicode	O
Technical	O
Note	O
.	O
</s>
<s>
SCSU	O
has	O
not	O
been	O
widely	O
adopted	O
,	O
as	O
it	O
is	O
not	O
suitable	O
for	O
MIME	B-Protocol
“	O
text	O
”	O
media	O
types	O
.	O
</s>
<s>
Usually	O
,	O
the	O
zip	B-General_Concept
,	O
bzip2	B-Application
,	O
and	O
other	O
industry	O
standard	O
algorithms	O
compact	O
larger	O
amounts	O
of	O
Unicode	O
text	O
more	O
efficiently	O
.	O
</s>
<s>
Both	O
SCSU	O
and	O
BOCU-1	B-General_Concept
are	O
IANA	O
registered	O
charsets	B-General_Concept
.	O
</s>
<s>
Code	O
points	O
from	O
U+0000	O
to	O
U+0020	O
are	O
encoded	O
in	O
BOCU-1	B-General_Concept
as	O
the	O
corresponding	O
byte	O
value	O
.	O
</s>
<s>
BOCU-1	B-General_Concept
offers	O
a	O
similar	O
robustness	O
also	O
for	O
input	O
texts	O
without	O
the	O
above-mentioned	O
values	O
with	O
the	O
special	O
reset	O
code	O
0xFF	O
.	O
</s>
<s>
The	O
use	O
of	O
0xFF	O
reset	O
bytes	O
is	O
not	O
recommended	O
in	O
the	O
BOCU-1	B-General_Concept
specification	O
,	O
because	O
it	O
conflicts	O
with	O
other	O
BOCU-1	B-General_Concept
design	O
goals	O
,	O
notably	O
the	O
binary	O
order	O
.	O
</s>
<s>
The	O
optional	O
use	O
of	O
a	O
signature	O
U+FEFF	O
at	O
the	O
begin	O
of	O
BOCU-1	B-General_Concept
encoded	O
texts	O
,	O
i.e.	O
</s>
<s>
the	O
BOCU-1	B-General_Concept
byte	O
sequence	O
FB	O
EE	O
28	O
,	O
changes	O
the	O
initial	O
state	O
U+0040	O
to	O
U+FEC0	O
.	O
</s>
<s>
In	O
other	O
words	O
,	O
the	O
signature	O
cannot	O
simply	O
be	O
stripped	O
as	O
in	O
most	O
other	O
Unicode	O
encoding	B-General_Concept
schemes	O
.	O
</s>
<s>
Adding	O
a	O
reset	O
byte	O
after	O
the	O
signature	O
(	O
FB	O
EE	O
28	O
FF	O
)	O
could	O
avoid	O
this	O
effect	O
,	O
but	O
the	O
BOCU-1	B-General_Concept
specification	O
does	O
not	O
recommend	O
this	O
practice	O
.	O
</s>
<s>
Excluding	O
the	O
thirteen	O
protected	O
code	O
points	O
encoded	O
as	O
single	O
octets	O
BOCU-1	B-General_Concept
can	O
use	O
octets	O
in	O
multi-byte	O
encodings	O
.	O
</s>
<s>
BOCU-1	B-General_Concept
needs	O
at	O
most	O
four	O
bytes	O
consisting	O
of	O
a	O
lead	O
byte	O
and	O
one	O
to	O
three	O
trail	O
bytes	O
.	O
</s>
<s>
Prior	O
to	O
16	O
November	O
2022	O
,	O
the	O
general	O
BOCU	B-General_Concept
algorithm	O
was	O
covered	O
by	O
United	O
States	O
Patent	O
#6	O
,	O
737	O
,	O
994	O
,	O
which	O
also	O
mentions	O
the	O
specific	O
BOCU-1	B-General_Concept
implementation	O
.	O
</s>
<s>
IBM	O
,	O
which	O
employed	O
both	O
of	O
the	O
inventors	O
of	O
BOCU-1	B-General_Concept
at	O
the	O
time	O
it	O
was	O
created	O
,	O
stated	O
in	O
the	O
Unicode	O
Technical	O
Note	O
that	O
implementers	O
of	O
a	O
"	O
fully	O
compliant	O
version	O
of	O
BOCU-1	B-General_Concept
"	O
had	O
to	O
contact	O
IBM	O
to	O
request	O
a	O
royalty-free	O
license	O
.	O
</s>
<s>
BOCU-1	B-General_Concept
is	O
the	O
only	O
Unicode	O
compression	O
scheme	O
described	O
on	O
the	O
Unicode	O
Web	O
site	O
that	O
is	O
known	O
to	O
have	O
been	O
encumbered	O
with	O
intellectual	O
property	O
restrictions	O
.	O
</s>
<s>
By	O
contrast	O
,	O
IBM	O
also	O
filed	O
for	O
a	O
patent	O
on	O
UTF-EBCDIC	O
,	O
but	O
it	O
chose	O
in	O
that	O
case	O
to	O
make	O
the	O
documentation	O
and	O
encoding	B-General_Concept
scheme	O
“	O
freely	O
available	O
to	O
anyone	O
concerned	O
towards	O
making	O
the	O
transformation	O
format	O
as	O
part	O
of	O
the	O
UCS	O
standards	O
,	O
”	O
instead	O
of	O
requiring	O
implementers	O
to	O
request	O
a	O
license	O
.	O
</s>
