<s>
A	O
TXT	B-Protocol
record	I-Protocol
(	O
short	O
for	O
text	O
record	O
)	O
is	O
a	O
type	O
of	O
resource	O
record	O
in	O
the	O
Domain	B-Protocol
name	I-Protocol
system	I-Protocol
(	O
DNS	B-Protocol
)	O
used	O
to	O
provide	O
the	O
ability	O
to	O
associate	O
arbitrary	O
text	O
with	O
a	O
host	O
or	O
other	O
name	O
,	O
such	O
as	O
human	O
readable	O
information	O
about	O
a	O
server	O
,	O
network	O
,	O
data	O
center	O
,	O
or	O
other	O
accounting	O
information	O
.	O
</s>
<s>
It	O
is	O
also	O
often	O
used	O
in	O
a	O
more	O
structured	O
fashion	O
to	O
record	O
small	O
amounts	O
of	O
machine-readable	O
data	O
into	O
the	O
DNS	B-Protocol
.	O
</s>
<s>
A	O
domain	O
may	O
have	O
multiple	O
TXT	B-Protocol
records	I-Protocol
associated	O
with	O
it	O
,	O
provided	O
the	O
DNS	B-Protocol
server	O
implementation	O
supports	O
this	O
.	O
</s>
<s>
Using	O
TXT	B-Protocol
records	I-Protocol
to	O
store	O
data	O
for	O
different	O
purposes	O
is	O
not	O
without	O
problems	O
.	O
</s>
<s>
The	O
DNS	B-Protocol
protocol	I-Protocol
specifies	O
that	O
when	O
a	O
client	O
queries	O
for	O
a	O
specific	O
record	O
type	O
(	O
e.g.	O
,	O
TXT	O
)	O
for	O
a	O
certain	O
domain	O
name	O
(	O
e.g.	O
,	O
example.com	O
)	O
,	O
all	O
records	O
of	O
that	O
type	O
must	O
be	O
returned	O
in	O
the	O
same	O
DNS	B-Protocol
message	O
.	O
</s>
<s>
That	O
may	O
lead	O
to	O
large	O
transactions	O
with	O
lots	O
of	O
"	O
unnecessary	O
"	O
information	O
being	O
transferred	O
and/or	O
uncertainty	O
about	O
which	O
TXT	B-Protocol
record	I-Protocol
to	O
use	O
.	O
</s>
<s>
There	O
are	O
two	O
ways	O
around	O
this	O
:	O
to	O
specify	O
a	O
domain	O
name	O
prefix	O
to	O
be	O
used	O
when	O
using	O
TXT	B-Protocol
records	I-Protocol
for	O
a	O
specific	O
purpose	O
(	O
e.g.	O
,	O
_domainkey.example.com	O
–	O
in	O
the	O
DKIM	B-Protocol
case	O
)	O
or	O
to	O
create	O
a	O
new	O
record	O
type	O
entirely	O
.	O
</s>
<s>
The	O
former	O
is	O
"	O
easy	O
"	O
because	O
it	O
does	O
n't	O
require	O
any	O
changes	O
to	O
the	O
DNS	B-Protocol
.	O
</s>
<s>
The	O
latter	O
is	O
sometimes	O
considered	O
"	O
cleaner	O
"	O
as	O
it	O
matches	O
the	O
design	O
of	O
the	O
DNS	B-Protocol
database	O
model	O
better	O
.	O
</s>
<s>
The	O
structure	O
of	O
the	O
TXT	B-Protocol
record	I-Protocol
is	O
specified	O
in	O
as	O
follows	O
.	O
</s>
<s>
It	O
explicitly	O
states	O
that	O
the	O
interpretation	O
of	O
the	O
string	O
is	O
context	O
dependent	O
,	O
and	O
that	O
the	O
data	O
is	O
treated	O
as	O
binary	O
inside	O
the	O
DNS	B-Protocol
.	O
</s>
<s>
Later	O
specifications	O
(	O
e.g.	O
,	O
–	O
DNS	B-Protocol
used	O
for	O
service	O
discovery	O
)	O
may	O
require	O
the	O
use	O
of	O
specific	O
encodings	O
for	O
specific	O
purposes	O
.	O
</s>
<s>
This	O
is	O
the	O
hex	O
returned	O
as	O
part	O
of	O
the	O
DNS	B-Protocol
response	O
from	O
example.com	O
when	O
queried	O
for	O
TXT	B-Protocol
records	I-Protocol
.	O
</s>
<s>
In	O
practice	O
,	O
services	O
using	O
TXT	B-Protocol
records	I-Protocol
often	O
do	O
not	O
follow	O
this	O
RFC	O
,	O
but	O
instead	O
have	O
their	O
own	O
specific	O
format	O
.	O
</s>
<s>
The	O
character	O
string	O
from	O
a	O
TXT	B-Protocol
record	I-Protocol
used	O
for	O
SPF	B-Protocol
:	O
</s>
