<s>
Reverse	B-Data_Structure
lookup	I-Data_Structure
is	O
a	O
procedure	O
of	O
using	O
a	O
value	O
to	O
retrieve	O
a	O
unique	B-Application
key	I-Application
in	O
an	O
associative	B-Application
array	I-Application
.	O
</s>
<s>
reverse	B-Protocol
DNS	I-Protocol
lookup	I-Protocol
,	O
which	O
provides	O
the	O
domain	O
name	O
associated	O
with	O
a	O
particular	O
IP	O
address	O
,	O
</s>
<s>
reverse	B-General_Concept
image	I-General_Concept
search	I-General_Concept
,	O
which	O
provides	O
similar	O
images	O
to	O
the	O
one	O
provided	O
.	O
</s>
