<s>
A	O
domain	B-Protocol
name	I-Protocol
registry	I-Protocol
is	O
a	O
database	O
of	O
all	O
domain	O
names	O
and	O
the	O
associated	O
registrant	O
information	O
in	O
the	O
top	O
level	O
domains	O
of	O
the	O
Domain	B-Protocol
Name	I-Protocol
System	I-Protocol
(	O
DNS	B-Protocol
)	O
of	O
the	O
Internet	O
that	O
enables	O
third	O
party	O
entities	O
to	O
request	O
administrative	O
control	O
of	O
a	O
domain	O
name	O
.	O
</s>
<s>
Most	O
registries	O
operate	O
on	O
the	O
top-level	O
and	O
second-level	O
of	O
the	O
DNS	B-Protocol
.	O
</s>
<s>
A	O
registry	B-Protocol
operator	I-Protocol
,	O
sometimes	O
called	O
a	O
network	B-Protocol
information	I-Protocol
center	I-Protocol
(	O
NIC	O
)	O
,	O
maintains	O
all	O
administrative	O
data	O
of	O
the	O
domain	O
and	O
generates	O
a	O
zone	O
file	O
which	O
contains	O
the	O
addresses	O
of	O
the	O
nameservers	B-Protocol
for	O
each	O
domain	O
.	O
</s>
<s>
It	O
may	O
also	O
fulfill	O
the	O
function	O
of	O
a	O
domain	B-Application
name	I-Application
registrar	I-Application
,	O
or	O
may	O
delegate	O
that	O
function	O
to	O
other	O
entities	O
.	O
</s>
<s>
Domain	O
names	O
are	O
managed	O
under	O
a	O
hierarchy	O
headed	O
by	O
the	O
Internet	O
Assigned	O
Numbers	O
Authority	O
(	O
IANA	O
)	O
,	O
which	O
manages	O
the	O
top	O
of	O
the	O
DNS	B-Protocol
tree	O
by	O
administrating	O
the	O
data	O
in	O
the	O
root	B-Application
nameservers	I-Application
.	O
</s>
<s>
IANA	O
also	O
operates	O
the	O
int	O
registry	O
for	O
intergovernmental	O
organizations	O
,	O
the	O
arpa	O
zone	O
for	O
protocol	O
administration	O
purposes	O
,	O
and	O
other	O
critical	O
zones	O
such	O
as	O
root-servers.net	O
.	O
</s>
<s>
IANA	O
delegates	O
all	O
other	O
domain	O
name	O
authority	O
to	O
other	O
domain	B-Protocol
name	I-Protocol
registries	I-Protocol
and	O
a	O
full	O
list	O
is	O
available	O
on	O
their	O
web	O
site	O
.	O
</s>
<s>
Country	B-Application
code	I-Application
top-level	I-Application
domains	I-Application
(	O
ccTLD	B-Application
)	O
are	O
delegated	O
by	O
IANA	O
to	O
national	O
registries	O
such	O
as	O
DENIC	O
in	O
Germany	O
and	O
Nominet	O
in	O
the	O
United	O
Kingdom	O
.	O
</s>
<s>
The	O
allocated	O
and	O
assigned	O
domain	O
names	O
are	O
made	O
available	O
by	O
registries	O
by	O
use	O
of	O
the	O
WHOIS	B-Protocol
system	O
and	O
via	O
their	O
domain	B-Protocol
name	I-Protocol
servers	I-Protocol
.	O
</s>
<s>
For	O
example	O
,	O
names	O
in	O
the	O
.com	O
top-level	O
domains	O
are	O
in	O
some	O
sense	O
sold	O
"	O
wholesale	O
"	O
at	O
a	O
regulated	O
price	O
by	O
VeriSign	B-Application
,	O
and	O
individual	O
domain	B-Application
name	I-Application
registrars	I-Application
sell	O
names	O
"	O
retail	O
"	O
to	O
businesses	O
and	O
consumers	O
.	O
</s>
<s>
Historically	O
,	O
domain	B-Protocol
name	I-Protocol
registries	I-Protocol
operated	O
on	O
a	O
first-come-first-served	O
system	O
of	O
allocation	O
but	O
may	O
reject	O
the	O
allocation	O
of	O
specific	O
domains	O
on	O
the	O
basis	O
of	O
political	O
,	O
religious	O
,	O
historical	O
,	O
legal	O
or	O
cultural	O
reasons	O
.	O
</s>
<s>
Domains	O
which	O
are	O
registered	O
with	O
ICANN	B-Application
registrars	O
,	O
generally	O
have	O
to	O
use	O
the	O
Uniform	O
Domain-Name	O
Dispute-Resolution	O
Policy	O
(	O
UDRP	O
)	O
,	O
however	O
,	O
Germany	O
's	O
DENIC	O
requires	O
people	O
to	O
use	O
the	O
German	O
civil	O
courts	O
,	O
and	O
Nominet	O
UK	O
deals	O
with	O
intellectual	O
property	O
and	O
other	O
disputes	O
through	O
its	O
own	O
dispute	O
resolution	O
service	O
.	O
</s>
<s>
Domain	B-Protocol
name	I-Protocol
registries	I-Protocol
may	O
also	O
impose	O
a	O
system	O
of	O
third-level	B-Protocol
domains	I-Protocol
on	O
users	O
.	O
</s>
<s>
DENIC	O
,	O
the	O
registry	O
for	O
Germany	O
(	O
.de	B-General_Concept
)	O
,	O
does	O
not	O
impose	O
third	B-Protocol
level	I-Protocol
domains	I-Protocol
.	O
</s>
<s>
AFNIC	O
,	O
the	O
registry	O
for	O
France	O
(	O
.fr	B-General_Concept
)	O
,	O
has	O
some	O
third	B-Protocol
level	I-Protocol
domains	I-Protocol
,	O
but	O
not	O
all	O
registrants	O
have	O
to	O
use	O
them	O
.	O
</s>
<s>
Many	O
ccTLDs	B-Application
have	O
moved	O
from	O
compulsory	O
third	O
or	O
fourth-level	O
domain	O
to	O
the	O
availability	O
of	O
registrations	O
of	O
second	O
level	O
domains	O
.	O
</s>
<s>
Among	O
them	O
are	O
.us	B-General_Concept
(	O
April	O
2002	O
)	O
,	O
.mx	O
(	O
May	O
2009	O
)	O
,	O
.co	B-Application
(	O
March	O
2010	O
)	O
,	O
and	O
.uk	B-Application
(	O
June	O
2014	O
)	O
.	O
</s>
