<s>
Contextual	B-Language
Query	I-Language
Language	I-Language
(	O
CQL	O
)	O
,	O
previously	O
known	O
as	O
Common	B-Language
Query	I-Language
Language	I-Language
,	O
is	O
a	O
formal	O
language	O
for	O
representing	O
queries	B-Library
to	O
information	B-Library
retrieval	I-Library
systems	I-Library
such	O
as	O
search	B-Application
engines	I-Application
,	O
bibliographic	O
catalogs	O
and	O
museum	O
collection	O
information	O
.	O
</s>
<s>
Based	O
on	O
the	O
semantics	B-Application
of	O
Z39.50	B-Protocol
,	O
its	O
design	O
objective	O
is	O
that	O
queries	B-Library
be	O
human	O
readable	O
and	O
writable	O
,	O
and	O
that	O
the	O
language	O
be	O
intuitive	O
while	O
maintaining	O
the	O
expressiveness	O
of	O
more	O
complex	O
query	B-Language
languages	I-Language
.	O
</s>
<s>
It	O
is	O
being	O
developed	O
and	O
maintained	O
by	O
the	O
Z39.50	B-Protocol
Maintenance	O
Agency	O
,	O
part	O
of	O
the	O
Library	O
of	O
Congress	O
.	O
</s>
<s>
Simple	O
queries	B-Library
:	O
</s>
<s>
Queries	B-Library
using	O
Boolean	O
logic	O
:	O
</s>
<s>
Queries	B-Library
accessing	O
publication	O
indexes	O
:	O
</s>
<s>
Queries	B-Library
based	O
on	O
the	O
proximity	O
of	O
words	O
to	O
each	O
other	O
in	O
a	O
document	O
:	O
</s>
<s>
Queries	B-Library
across	O
multiple	O
dimensions	O
:	O
</s>
<s>
Queries	B-Library
based	O
on	O
relevance	O
:	O
</s>
