<s>
Soundex	B-Algorithm
is	O
a	O
phonetic	B-Algorithm
algorithm	I-Algorithm
for	O
indexing	O
names	O
by	O
sound	O
,	O
as	O
pronounced	O
in	O
English	O
.	O
</s>
<s>
The	O
goal	O
is	O
for	O
homophones	O
to	O
be	O
encoded	B-Algorithm
to	O
the	O
same	O
representation	O
so	O
that	O
they	O
can	O
be	O
matched	O
despite	O
minor	O
differences	O
in	O
spelling	O
.	O
</s>
<s>
The	O
algorithm	O
mainly	O
encodes	O
consonants	O
;	O
a	O
vowel	O
will	O
not	O
be	O
encoded	B-Algorithm
unless	O
it	O
is	O
the	O
first	O
letter	O
.	O
</s>
<s>
Soundex	B-Algorithm
is	O
the	O
most	O
widely	O
known	O
of	O
all	O
phonetic	B-Algorithm
algorithms	I-Algorithm
(	O
in	O
part	O
because	O
it	O
is	O
a	O
standard	O
feature	O
of	O
popular	O
database	O
software	O
such	O
as	O
IBM	B-Application
Db2	I-Application
,	O
PostgreSQL	B-Application
,	O
MySQL	B-Application
,	O
SQLite	B-Language
,	O
Ingres	B-Application
,	O
MS	B-Application
SQL	I-Application
Server	I-Application
,	O
Oracle	B-General_Concept
,	O
ClickHouse	B-Language
,	O
and	O
SAP	B-Application
ASE	I-Application
.	O
)	O
</s>
<s>
Improvements	O
to	O
Soundex	B-Algorithm
are	O
the	O
basis	O
for	O
many	O
modern	O
phonetic	B-Algorithm
algorithms	I-Algorithm
.	O
</s>
<s>
Soundex	B-Algorithm
was	O
developed	O
by	O
Robert	O
C	O
.	O
Russell	O
and	O
Margaret	O
King	O
Odell	O
and	O
patented	O
in	O
1918	O
and	O
1922	O
.	O
</s>
<s>
A	O
variation	O
,	O
American	O
Soundex	B-Algorithm
,	O
was	O
used	O
in	O
the	O
1930s	O
for	O
a	O
retrospective	O
analysis	O
of	O
the	O
US	O
censuses	O
from	O
1890	O
through	O
1920	O
.	O
</s>
<s>
The	O
Soundex	B-Algorithm
code	I-Algorithm
came	O
to	O
prominence	O
in	O
the	O
1960s	O
when	O
it	O
was	O
the	O
subject	O
of	O
several	O
articles	O
in	O
the	O
Communications	O
and	O
Journal	O
of	O
the	O
Association	O
for	O
Computing	O
Machinery	O
,	O
and	O
especially	O
when	O
described	O
in	O
Donald	O
Knuth	O
's	O
The	B-General_Concept
Art	I-General_Concept
of	I-General_Concept
Computer	I-General_Concept
Programming	I-General_Concept
.	O
</s>
<s>
The	O
National	O
Archives	O
and	O
Records	O
Administration	O
(	O
NARA	O
)	O
maintains	O
the	O
current	O
rule	O
set	O
for	O
the	O
official	O
implementation	O
of	O
Soundex	B-Algorithm
used	O
by	O
the	O
U.S.	O
government	O
.	O
</s>
<s>
These	O
encoding	B-Algorithm
rules	O
are	O
available	O
from	O
NARA	O
,	O
upon	O
request	O
,	O
in	O
the	O
form	O
of	O
General	O
Information	O
Leaflet	O
55	O
,	O
"	O
Using	O
the	O
Census	O
Soundex	B-Algorithm
"	O
.	O
</s>
<s>
The	O
Soundex	B-Algorithm
code	I-Algorithm
for	O
a	O
name	O
consists	O
of	O
a	O
letter	O
followed	O
by	O
three	O
numerical	O
digits	O
:	O
the	O
letter	O
is	O
the	O
first	O
letter	O
of	O
the	O
name	O
,	O
and	O
the	O
digits	O
encode	O
the	O
remaining	O
consonants	O
.	O
</s>
<s>
Consonants	O
at	O
a	O
similar	O
place	O
of	O
articulation	O
share	O
the	O
same	O
digit	O
so	O
,	O
for	O
example	O
,	O
the	O
labial	O
consonants	O
B	O
,	O
F	O
,	O
P	O
,	O
and	O
V	O
are	O
each	O
encoded	B-Algorithm
as	O
the	O
number	O
1	O
.	O
</s>
<s>
The	O
following	O
algorithm	O
is	O
followed	O
by	O
most	O
SQL	O
languages	O
(	O
excluding	O
PostgreSQL	B-Application
)	O
:	O
</s>
<s>
In	O
designing	O
an	O
application	O
,	O
which	O
combines	O
SQL	O
and	O
a	O
programming	O
language	O
,	O
the	O
architect	O
must	O
decide	O
whether	O
to	O
do	O
all	O
of	O
the	O
Soundex	B-Algorithm
encoding	B-Algorithm
in	O
the	O
SQL	O
server	O
or	O
all	O
in	O
the	O
programming	O
language	O
.	O
</s>
<s>
The	O
MySQL	B-Application
implementation	O
can	O
return	O
more	O
than	O
4	O
characters	O
.	O
</s>
<s>
A	O
similar	O
algorithm	O
called	O
"	O
Reverse	O
Soundex	B-Algorithm
"	O
prefixes	O
the	O
last	O
letter	O
of	O
the	O
name	O
instead	O
of	O
the	O
first	O
.	O
</s>
<s>
The	O
New	B-Algorithm
York	I-Algorithm
State	I-Algorithm
Identification	I-Algorithm
and	I-Algorithm
Intelligence	I-Algorithm
System	I-Algorithm
(	O
NYSIIS	B-Algorithm
)	O
algorithm	O
was	O
introduced	O
in	O
1970	O
as	O
an	O
improvement	O
to	O
the	O
Soundex	B-Algorithm
algorithm	O
.	O
</s>
<s>
NYSIIS	B-Algorithm
handles	O
some	O
multi-character	O
n-grams	B-Language
and	O
maintains	O
relative	O
vowel	O
positioning	O
,	O
whereas	O
Soundex	B-Algorithm
does	O
not	O
.	O
</s>
<s>
Daitch	B-Algorithm
–	I-Algorithm
Mokotoff	I-Algorithm
Soundex	I-Algorithm
(	O
D	O
–	O
M	O
Soundex	B-Algorithm
)	O
was	O
developed	O
in	O
1985	O
by	O
genealogist	O
Gary	O
Mokotoff	O
and	O
later	O
improved	O
by	O
genealogist	O
Randy	O
Daitch	O
because	O
of	O
problems	O
they	O
encountered	O
while	O
trying	O
to	O
apply	O
the	O
Russell	O
Soundex	B-Algorithm
to	O
Jews	O
with	O
Germanic	O
or	O
Slavic	O
surnames	O
(	O
such	O
as	O
Moskowitz	O
vs.	O
Moskovitz	O
or	O
Levine	O
vs.	O
Lewin	O
)	O
.	O
</s>
<s>
D	O
–	O
M	O
Soundex	B-Algorithm
is	O
sometimes	O
referred	O
to	O
as	O
"	O
Jewish	O
Soundex	B-Algorithm
"	O
or	O
"	O
Eastern	O
European	O
Soundex	B-Algorithm
"	O
,	O
although	O
the	O
authors	O
discourage	O
the	O
use	O
of	O
those	O
names	O
.	O
</s>
<s>
The	O
D	O
–	O
M	O
Soundex	B-Algorithm
algorithm	O
can	O
return	O
as	O
many	O
as	O
32	O
individual	O
phonetic	B-Algorithm
encodings	I-Algorithm
for	O
a	O
single	O
name	O
.	O
</s>
<s>
Results	O
of	O
D-M	O
Soundex	B-Algorithm
are	O
returned	O
in	O
an	O
all-numeric	O
format	O
between	O
100000	O
and	O
999999	O
.	O
</s>
<s>
This	O
algorithm	O
is	O
much	O
more	O
complex	O
than	O
Russell	O
Soundex	B-Algorithm
.	O
</s>
<s>
As	O
a	O
response	O
to	O
deficiencies	O
in	O
the	O
Soundex	B-Algorithm
algorithm	O
,	O
Lawrence	B-Algorithm
Philips	I-Algorithm
developed	O
the	O
Metaphone	B-Algorithm
algorithm	O
in	O
1990	O
.	O
</s>
<s>
Philips	O
developed	O
an	O
improvement	O
to	O
Metaphone	B-Algorithm
in	O
2000	O
,	O
which	O
he	O
called	O
Double	O
Metaphone	B-Algorithm
.	O
</s>
<s>
Double	O
Metaphone	B-Algorithm
includes	O
a	O
much	O
larger	O
encoding	B-Algorithm
rule	O
set	O
than	O
its	O
predecessor	O
,	O
handles	O
a	O
subset	O
of	O
non-Latin	O
characters	O
,	O
and	O
returns	O
a	O
primary	O
and	O
a	O
secondary	O
encoding	B-Algorithm
to	O
account	O
for	O
different	O
pronunciations	O
of	O
a	O
single	O
word	O
in	O
English	O
.	O
</s>
<s>
Philips	O
created	O
Metaphone	B-Algorithm
3	O
as	O
a	O
further	O
revision	O
in	O
2009	O
to	O
provide	O
a	O
professional	O
version	O
that	O
provides	O
a	O
much	O
higher	O
percentage	O
of	O
correct	O
encodings	B-Algorithm
for	O
English	O
words	O
,	O
non-English	O
words	O
familiar	O
to	O
Americans	O
,	O
and	O
first	O
and	O
last	O
names	O
found	O
in	O
the	O
United	O
States	O
.	O
</s>
