<s>
A	O
general-purpose	B-Protocol
markup	I-Protocol
language	I-Protocol
is	O
a	O
markup	O
language	O
that	O
is	O
used	O
for	O
more	O
than	O
one	O
purpose	O
or	O
situation	O
.	O
</s>
<s>
Other	O
,	O
more	O
specialized	O
domain-specific	B-Language
markup	O
languages	O
are	O
often	O
based	O
upon	O
these	O
languages	O
.	O
</s>
<s>
For	O
example	O
,	O
HTML	B-Language
4.1	I-Language
and	O
earlier	O
are	O
domain-specific	B-Language
markup	O
languages	O
(	O
for	O
webpages	O
)	O
,	O
and	O
are	O
based	O
on	O
the	O
syntax	O
of	O
SGML	B-Language
,	O
which	O
is	O
a	O
general-purpose	B-Protocol
markup	I-Protocol
language	I-Protocol
.	O
</s>
<s>
Notable	O
general-purpose	B-Protocol
markup	I-Protocol
languages	I-Protocol
include	O
:	O
</s>
