<s>
Document	B-Language
Structure	I-Language
Description	I-Language
,	O
or	O
DSD	O
,	O
is	O
a	O
schema	B-Language
language	O
for	O
XML	B-Protocol
,	O
that	O
is	O
,	O
a	O
language	O
for	O
describing	O
valid	B-Protocol
XML	I-Protocol
documents	I-Protocol
.	O
</s>
<s>
It	O
's	O
an	O
alternative	O
to	O
DTD	B-Language
or	O
the	O
W3C	O
XML	B-Language
Schema	I-Language
.	O
</s>
<s>
This	O
says	O
that	O
element	O
named	O
"	O
foo	O
"	O
in	O
the	O
XML	B-Language
namespace	I-Language
"	O
http://example.com	O
"	O
may	O
have	O
two	O
attributes	O
,	O
named	O
"	O
first	O
"	O
and	O
"	O
second	O
"	O
.	O
</s>
<s>
One	O
XML	B-Protocol
document	I-Protocol
that	O
would	O
be	O
valid	O
according	O
to	O
the	O
above	O
DSD	O
would	O
be	O
:	O
</s>
