<s>
Sign	B-General_Concept
in	I-General_Concept
with	I-General_Concept
Apple	I-General_Concept
is	O
a	O
single	O
sign-on	O
provider	O
operated	O
by	O
Apple	O
Inc.	O
,	O
introduced	O
on	O
June	O
3	O
,	O
2019	O
at	O
Apple	O
's	O
2019	O
Worldwide	O
Developers	O
Conference	O
(	O
WWDC	O
)	O
in	O
iOS	B-Operating_System
13	I-Operating_System
.	O
</s>
<s>
Users	O
can	O
opt	O
for	O
the	O
email	O
address	O
associated	O
with	O
their	O
Apple	B-General_Concept
ID	I-General_Concept
or	O
choose	O
the	O
"	O
Hide	O
My	O
Email	O
"	O
option	O
to	O
generate	O
a	O
disposable	O
email	O
address	O
specific	O
to	O
the	O
service	O
;	O
these	O
addresses	O
end	O
in	O
the	O
privaterelay.appleid.com	O
domain	O
.	O
</s>
<s>
The	O
service	O
is	O
compatible	O
with	O
the	O
OAuth	O
2.0	O
and	O
OpenID	O
Connect	O
standards	O
,	O
and	O
integrates	O
with	O
Face	O
ID	O
and	O
Touch	O
ID	O
on	O
iOS	B-Application
,	O
iPadOS	B-Operating_System
,	O
and	O
macOS	B-Application
.	O
</s>
<s>
On	O
September	O
12	O
,	O
2019	O
,	O
Apple	O
updated	O
the	O
App	B-Operating_System
Store	I-Operating_System
Review	I-Operating_System
Guidelines	I-Operating_System
to	O
stipulate	O
that	O
developers	O
whose	O
apps	O
use	O
at	O
least	O
one	O
third-party	O
login	O
service	O
must	O
implement	O
Sign	B-General_Concept
in	I-General_Concept
with	I-General_Concept
Apple	I-General_Concept
,	O
with	O
exceptions	O
for	O
apps	O
that	O
function	O
exclusively	O
as	O
a	O
client	O
for	O
a	O
specific	O
service	O
(	O
such	O
as	O
the	O
Twitter	B-Application
app	O
)	O
,	O
that	O
use	O
a	O
login	O
service	O
backed	O
by	O
a	O
citizen	O
identification	O
system	O
,	O
or	O
that	O
are	O
developed	O
to	O
work	O
exclusively	O
with	O
a	O
company	O
's	O
first-party	O
login	O
service	O
.	O
</s>
<s>
Apple	O
's	O
human	B-Application
interface	I-Application
guidelines	I-Application
require	O
Sign	B-General_Concept
in	I-General_Concept
with	I-General_Concept
Apple	I-General_Concept
buttons	O
to	O
be	O
no	O
less	O
prominent	O
than	O
other	O
sign-in	O
services	O
,	O
and	O
to	O
appear	O
"	O
above	O
the	O
fold	O
"	O
without	O
the	O
user	O
having	O
to	O
scroll	O
.	O
</s>
<s>
For	O
use	O
outside	O
of	O
iOS	B-Application
apps	O
,	O
Apple	O
also	O
offers	O
a	O
JavaScript	B-Language
library	O
to	O
implement	O
Sign	B-General_Concept
in	I-General_Concept
with	I-General_Concept
Apple	I-General_Concept
on	O
Android	B-Application
and	O
the	O
web	O
.	O
</s>
