<s>
A	O
QName	B-Language
,	O
or	O
qualified	B-Protocol
name	I-Protocol
,	O
is	O
the	O
fully	B-Protocol
qualified	I-Protocol
name	I-Protocol
of	O
an	O
element	O
,	O
attribute	O
,	O
or	O
identifier	O
in	O
an	O
XML	B-Protocol
document	I-Protocol
.	O
</s>
<s>
A	O
QName	B-Language
concisely	O
associates	O
the	O
URI	B-Protocol
of	O
an	O
XML	B-Language
namespace	I-Language
with	O
the	O
local	O
name	O
of	O
an	O
element	O
,	O
attribute	O
,	O
or	O
identifier	O
in	O
that	O
namespace	O
.	O
</s>
<s>
To	O
make	O
this	O
association	O
,	O
the	O
QName	B-Language
assigns	O
the	O
local	O
name	O
a	O
prefix	O
that	O
corresponds	O
to	O
its	O
namespace	O
.	O
</s>
<s>
In	O
all	O
,	O
the	O
QName	B-Language
comprises	O
the	O
URI	B-Protocol
of	O
the	O
XML	B-Language
namespace	I-Language
,	O
the	O
prefix	O
,	O
and	O
the	O
local	O
name	O
.	O
</s>
<s>
The	O
World	O
Wide	O
Web	O
Consortium	O
introduced	O
the	O
QName	B-Language
convention	O
in	O
the	O
1999	O
specification	O
"	O
Namespaces	B-Language
in	I-Language
XML	I-Language
"	O
.	O
</s>
<s>
Since	O
URI	B-Protocol
references	O
can	O
be	O
long	O
and	O
may	O
contain	O
prohibited	O
characters	O
for	O
element/attribute	O
naming	O
,	O
QNames	B-Language
are	O
used	O
to	O
create	O
a	O
mapping	O
between	O
the	O
URI	B-Protocol
and	O
a	O
namespace	O
prefix	O
.	O
</s>
<s>
The	O
mapping	O
enables	O
the	O
abbreviation	O
of	O
URIs	B-Protocol
,	O
therefore	O
it	O
achieves	O
a	O
more	O
convenient	O
way	O
to	O
write	O
XML	B-Protocol
documents	I-Protocol
(	O
see	O
example	O
below	O
)	O
.	O
</s>
<s>
QNames	B-Language
are	O
formally	O
defined	O
by	O
the	O
W3C	O
as	O
:	O
</s>
<s>
Whereby	O
the	O
Prefix	O
is	O
used	O
as	O
placeholder	O
for	O
the	O
namespace	O
and	O
the	O
LocalPart	O
as	O
the	O
local	O
part	O
of	O
the	O
qualified	B-Protocol
name	I-Protocol
.	O
</s>
<s>
In	O
line	O
two	O
the	O
prefix	O
"	O
x	O
"	O
is	O
declared	O
to	O
be	O
associated	O
with	O
the	O
URI	B-Protocol
"	O
http://example.com/ns/foo	O
"	O
.	O
</s>
<s>
Subsequently	O
the	O
tag	O
"	O
x:p	O
"	O
is	O
a	O
valid	O
QName	B-Language
because	O
it	O
uses	O
the	O
"	O
x	O
"	O
as	O
namespace	O
reference	O
and	O
"	O
p	O
"	O
as	O
local	O
part	O
.	O
</s>
<s>
The	O
tag	O
"	O
doc	O
"	O
is	O
also	O
a	O
valid	O
QName	B-Language
,	O
but	O
it	O
consists	O
only	O
of	O
a	O
local	O
part	O
.	O
</s>
