<s>
nofollow	B-Application
is	O
a	O
setting	O
on	O
a	O
web	O
page	O
hyperlink	O
that	O
directs	O
search	B-Application
engines	I-Application
not	O
to	O
use	O
the	O
link	O
for	O
page	B-Algorithm
ranking	I-Algorithm
calculations	O
.	O
</s>
<s>
It	O
is	O
specified	O
in	O
the	O
page	O
as	O
a	O
type	O
of	O
link	B-General_Concept
relation	I-General_Concept
;	O
that	O
is	O
:	O
<a rel="nofollow" ...>	O
.	O
</s>
<s>
Because	O
search	B-Application
engines	I-Application
often	O
calculate	O
a	O
site	O
's	O
importance	O
according	O
to	O
the	O
number	O
of	O
hyperlinks	O
from	O
other	O
sites	O
,	O
the	O
nofollow	B-Application
setting	O
allows	O
website	O
authors	O
to	O
indicate	O
that	O
the	O
presence	O
of	O
a	O
link	O
is	O
not	O
an	O
endorsement	O
of	O
the	O
target	O
site	O
's	O
importance	O
.	O
</s>
<s>
The	O
nofollow	B-Application
value	O
was	O
originally	O
suggested	O
to	O
stop	O
comment	O
spam	O
in	O
blogs	O
.	O
</s>
<s>
Believing	O
that	O
comment	O
spam	O
affected	O
the	O
entire	O
blogging	O
community	O
,	O
in	O
early	O
2005	O
Google	B-Application
's	I-Application
Matt	O
Cutts	O
and	O
Blogger	B-Application
's	O
Jason	O
Shellen	O
proposed	O
the	O
value	O
to	O
address	O
the	O
problem	O
.	O
</s>
<s>
The	O
specification	O
for	O
nofollow	B-Application
is	O
copyrighted	O
2005	O
–	O
07	O
by	O
the	O
authors	O
and	O
subject	O
to	O
a	O
royalty-free	O
patent	O
policy	O
,	O
e.g.	O
</s>
<s>
Google	B-Application
announced	O
in	O
early	O
2005	O
that	O
hyperlinks	O
with	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
would	O
not	O
influence	O
the	O
link	O
target	O
's	O
PageRank	B-Algorithm
.	O
</s>
<s>
In	O
addition	O
,	O
the	O
Yahoo	B-Application
and	O
Bing	B-Application
search	I-Application
engines	I-Application
also	O
respect	O
this	O
attribute	O
value	O
.	O
</s>
<s>
On	O
June	O
15	O
,	O
2009	O
,	O
Google	B-Application
software	O
engineer	O
Matt	O
Cutts	O
announced	O
on	O
his	O
blog	O
that	O
GoogleBot	O
changed	O
the	O
way	O
it	O
treats	O
nofollowed	O
links	O
,	O
in	O
order	O
to	O
prevent	O
webmasters	O
from	O
using	O
nofollow	B-Application
for	O
PageRank	B-Algorithm
sculpting	O
.	O
</s>
<s>
Prior	O
to	O
this	O
,	O
webmasters	O
would	O
place	O
nofollow	B-Application
tags	O
on	O
some	O
of	O
their	O
links	O
in	O
order	O
to	O
maximize	O
the	O
PageRank	B-Algorithm
of	O
the	O
other	O
pages	O
.	O
</s>
<s>
As	O
a	O
result	O
of	O
this	O
change	O
,	O
the	O
usage	O
of	O
nofollow	B-Application
leads	O
to	O
evaporation	O
of	O
pagerank	B-Algorithm
of	O
outgoing	O
normal	O
links	O
as	O
they	O
started	O
counting	O
total	O
links	O
while	O
calculating	O
page	B-Algorithm
rank	I-Algorithm
.	O
</s>
<s>
The	O
new	O
system	O
divides	O
page	B-Algorithm
rank	I-Algorithm
by	O
total	O
number	O
of	O
outgoing	O
links	O
irrespective	O
of	O
nofollow	B-Application
or	O
follow	O
links	O
,	O
but	O
passes	O
the	O
page	B-Algorithm
rank	I-Algorithm
only	O
through	O
follow	O
or	O
normal	O
links	O
.	O
</s>
<s>
Cutts	O
explained	O
that	O
if	O
a	O
page	O
has	O
5	O
normal	O
links	O
and	O
5	O
nofollow	B-Application
outgoing	O
links	O
,	O
the	O
page	B-Algorithm
rank	I-Algorithm
will	O
be	O
divided	O
by	O
10	O
links	O
and	O
one	O
share	O
is	O
passed	O
by	O
5	O
normal	O
links	O
.	O
</s>
<s>
However	O
,	O
as	O
of	O
March	O
1	O
2020	O
,	O
Google	B-Application
is	O
treating	O
the	O
nofollow	B-Application
link	O
attribute	O
as	O
a	O
hint	O
,	O
rather	O
than	O
a	O
directive	O
,	O
for	O
crawling	O
and	O
indexing	O
purposes	O
.	O
</s>
<s>
While	O
all	O
engines	O
that	O
use	O
the	O
nofollow	B-Application
value	O
exclude	O
links	O
that	O
use	O
it	O
from	O
their	O
ranking	O
calculation	O
,	O
the	O
details	O
about	O
the	O
exact	O
interpretation	O
of	O
it	O
vary	O
from	O
search	B-Application
engine	I-Application
to	O
search	B-Application
engine	I-Application
.	O
</s>
<s>
Google	B-Application
states	O
that	O
their	O
engine	O
"	O
in	O
general	O
"	O
takes	O
"	O
nofollow	B-Application
"	O
literally	O
and	O
does	O
not	O
"	O
follow	O
"	O
the	O
link	O
.	O
</s>
<s>
Yahoo	B-Application
!	I-Application
</s>
<s>
Bing	B-Application
may	O
not	O
follow	O
it	O
,	O
but	O
excludes	O
it	O
from	O
their	O
ranking	O
calculation	O
.	O
</s>
<s>
Ask.com	B-Application
also	O
respects	O
the	O
attribute	O
.	O
</s>
<s>
Baidu	B-Application
appears	O
to	O
respect	O
the	O
attribute	O
.	O
</s>
<s>
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
ActionGoogle	O
Yahoo	B-Application
!	I-Application
</s>
<s>
More	O
sophisticated	O
server	O
software	O
could	O
suppress	O
the	O
nofollow	B-Application
for	O
links	O
submitted	O
by	O
trusted	O
users	O
like	O
those	O
registered	O
for	O
a	O
long	O
time	O
,	O
on	O
a	O
whitelist	O
,	O
or	O
with	O
an	O
acceptable	O
karma	O
level	O
.	O
</s>
<s>
Some	O
server	O
software	O
adds	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
to	O
pages	O
that	O
have	O
been	O
recently	O
edited	O
but	O
omits	O
it	O
from	O
stable	O
pages	O
,	O
under	O
the	O
theory	O
that	O
stable	O
pages	O
will	O
have	O
had	O
offending	O
links	O
removed	O
by	O
human	O
editors	O
.	O
</s>
<s>
The	O
widely	O
used	O
blogging	O
platform	O
WordPress	B-Application
versions	O
1.5	O
and	O
above	O
automatically	O
assign	O
the	O
nofollow	B-Application
attribute	O
to	O
all	O
user-submitted	O
links	O
(	O
comment	O
data	O
,	O
commenter	O
URI	O
,	O
etc	O
.	O
)	O
.	O
</s>
<s>
However	O
,	O
there	O
are	O
several	O
free	O
plugins	O
available	O
that	O
automatically	O
remove	O
the	O
nofollow	B-Application
attribute	O
value	O
.	O
</s>
<s>
MediaWiki	B-Application
software	I-Application
,	O
which	O
powers	O
Wikipedia	O
,	O
was	O
equipped	O
with	O
nofollow	B-Application
support	O
soon	O
after	O
the	O
initial	O
announcement	O
in	O
2005	O
.	O
</s>
<s>
Initially	O
,	O
after	O
a	O
discussion	O
,	O
it	O
was	O
decided	O
not	O
to	O
use	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
in	O
articles	O
and	O
to	O
use	O
a	O
URL	O
blacklist	O
instead	O
.	O
</s>
<s>
In	O
May	O
2006	O
,	O
a	O
patch	O
to	O
MediaWiki	B-Application
software	I-Application
allowed	O
enabling	O
nofollow	B-Application
selectively	O
in	O
namespaces	O
.	O
</s>
<s>
Following	O
increasing	O
spam	O
problems	O
and	O
a	O
within-Foundation	O
request	O
from	O
co-founder	O
Jimmy	O
Wales	O
,	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
was	O
added	O
to	O
article-space	O
links	O
in	O
January	O
2007	O
.	O
</s>
<s>
Other	O
websites	O
like	O
Slashdot	O
,	O
with	O
high	O
user	O
participation	O
,	O
add	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
only	O
for	O
potentially	O
misbehaving	O
users	O
.	O
</s>
<s>
Slashdot	O
also	O
uses	O
the	O
poster	O
's	O
karma	O
as	O
a	O
determinant	O
in	O
attaching	O
a	O
nofollow	B-Application
tag	O
to	O
user-submitted	O
links	O
.	O
</s>
<s>
Social	O
bookmarking	O
and	O
photo	O
sharing	O
websites	O
that	O
use	O
the	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
tag	O
for	O
their	O
outgoing	O
links	O
include	O
YouTube	B-General_Concept
and	O
Digg.com	B-Application
(	O
for	O
most	O
links	O
)	O
;	O
websites	O
that	O
do	O
n't	O
use	O
the	O
rel	B-Application
=	I-Application
"	I-Application
nofollow	I-Application
"	I-Application
tag	O
include	O
Yahoo	B-Application
!	I-Application
</s>
<s>
My	O
Web	O
2.0	O
,	O
Technorati	B-Application
Favs	O
,	O
and	O
Propeller.com	B-Application
(	O
no	O
longer	O
an	O
active	O
website	O
)	O
.	O
</s>
<s>
Search	B-Application
engine	I-Application
optimization	O
professionals	O
started	O
using	O
the	O
nofollow	B-Application
attribute	O
to	O
control	O
the	O
flow	O
of	O
PageRank	B-Algorithm
within	O
a	O
website	O
,	O
but	O
Google	B-Application
has	O
since	O
corrected	O
this	O
error	O
,	O
and	O
any	O
link	O
with	O
a	O
nofollow	B-Application
attribute	O
decreases	O
the	O
PageRank	B-Algorithm
that	O
the	O
page	O
can	O
pass	O
on	O
.	O
</s>
<s>
This	O
practice	O
is	O
known	O
as	O
"	O
PageRank	B-Algorithm
sculpting	O
"	O
.	O
</s>
<s>
nofollow	B-Application
was	O
designed	O
to	O
control	O
the	O
flow	O
of	O
PageRank	B-Algorithm
from	O
one	O
website	O
to	O
another	O
.	O
</s>
<s>
However	O
,	O
some	O
SEOs	O
have	O
suggested	O
that	O
a	O
nofollow	B-Application
used	O
for	O
an	O
internal	O
link	O
should	O
work	O
just	O
like	O
nofollow	B-Application
used	O
for	O
external	O
links	O
.	O
</s>
<s>
Several	O
SEOs	O
have	O
suggested	O
that	O
pages	O
such	O
as	O
"	O
About	O
Us	O
"	O
,	O
"	O
Terms	O
of	O
Service	O
"	O
,	O
"	O
Contact	O
Us	O
"	O
,	O
and	O
"	O
Privacy	O
Policy	O
"	O
pages	O
are	O
not	O
important	O
enough	O
to	O
earn	O
PageRank	B-Algorithm
,	O
and	O
so	O
should	O
have	O
nofollow	B-Application
on	O
internal	O
links	O
pointing	O
to	O
them	O
.	O
</s>
<s>
Google	B-Application
employee	O
Matt	O
Cutts	O
has	O
provided	O
indirect	O
responses	O
on	O
the	O
subject	O
,	O
but	O
has	O
never	O
publicly	O
endorsed	O
this	O
point	O
of	O
view	O
.	O
</s>
<s>
Site	O
search	O
proponents	O
have	O
pointed	O
out	O
that	O
visitors	O
do	O
search	O
for	O
these	O
types	O
of	O
pages	O
,	O
so	O
using	O
nofollow	B-Application
on	O
internal	O
links	O
pointing	O
to	O
them	O
may	O
make	O
it	O
difficult	O
or	O
impossible	O
for	O
visitors	O
to	O
find	O
these	O
pages	O
in	O
site	O
searches	O
powered	O
by	O
major	O
search	B-Application
engines	I-Application
.	O
</s>
<s>
Although	O
proponents	O
of	O
use	O
of	O
nofollow	B-Application
on	O
internal	O
links	O
have	O
cited	O
an	O
inappropriate	O
attribution	O
to	O
Matt	O
Cutts	O
(	O
see	O
Matt	O
's	O
clarifying	O
comment	O
,	O
rebutting	O
the	O
attributed	O
statement	O
)	O
as	O
support	O
for	O
using	O
the	O
technique	O
,	O
Cutts	O
himself	O
never	O
actually	O
endorsed	O
the	O
idea	O
.	O
</s>
<s>
Several	O
Google	B-Application
employees	O
(	O
including	O
Matt	O
Cutts	O
)	O
have	O
urged	O
Webmasters	O
not	O
to	O
focus	O
on	O
manipulating	O
internal	O
PageRank	B-Algorithm
.	O
</s>
<s>
Google	B-Application
employee	O
Adam	O
Lasnik	O
has	O
advised	O
webmasters	O
that	O
there	O
are	O
better	O
ways	O
(	O
e.g.	O
</s>
<s>
click	O
hierarchy	O
)	O
than	O
nofollow	B-Application
to	O
"	O
sculpt	O
a	O
bit	O
of	O
PageRank	B-Algorithm
"	O
,	O
but	O
that	O
it	O
is	O
available	O
and	O
"	O
we	O
're	O
not	O
going	O
to	O
frown	O
upon	O
it	O
"	O
.	O
</s>
<s>
YouTube	B-General_Concept
,	O
a	O
Google	B-Application
company	O
,	O
uses	O
nofollow	B-Application
on	O
a	O
number	O
of	O
internal	O
"	O
help	O
"	O
and	O
"	O
share	O
"	O
links	O
.	O
</s>
<s>
On	O
September	O
10	O
,	O
2019	O
,	O
Google	B-Application
announced	O
two	O
additional	O
ways	O
for	O
webmasters	O
to	O
qualify	O
the	O
relationship	O
of	O
outbound	O
hyperlinks	O
.	O
</s>
<s>
In	O
2019	O
,	O
WordPress	B-Application
announced	O
plans	O
to	O
convert	O
all	O
blog	O
comments	O
into	O
rel	O
=	O
"	O
ugc	O
"	O
.	O
</s>
<s>
These	O
"	O
hint	O
"	O
link	O
attributes	O
address	O
some	O
of	O
the	O
criticisms	O
of	O
nofollow	B-Application
by	O
allowing	O
webmasters	O
to	O
denote	O
outbound	O
links	O
that	O
lack	O
"	O
the	O
weight	O
of	O
a	O
first-party	O
endorsement	O
"	O
,	O
but	O
are	O
not	O
necessarily	O
spam	O
.	O
</s>
