<s>
Setext	B-Language
(	O
Structure	O
Enhanced	O
Text	O
)	O
is	O
a	O
lightweight	B-Protocol
markup	I-Protocol
language	I-Protocol
used	O
to	O
format	O
plain	O
text	O
documents	O
such	O
as	O
e-newsletters	O
,	O
Usenet	B-Application
postings	O
,	O
and	O
e-mails	O
.	O
</s>
<s>
In	O
contrast	O
to	O
some	O
other	O
markup	O
languages	O
(	O
such	O
as	O
HTML	B-Language
)	O
,	O
the	O
markup	O
is	O
easily	O
readable	O
without	O
any	O
parsing	B-Language
or	O
special	O
software	O
.	O
</s>
<s>
Setext	B-Language
was	O
first	O
introduced	O
in	O
1991	O
by	O
Ian	O
Feldman	O
for	O
use	O
in	O
the	O
TidBITS	O
electronic	O
newsletter	O
.	O
</s>
<s>
Setext	B-Language
allows	O
viewing	O
of	O
marked-up	O
documents	O
without	O
special	O
viewing	O
software	O
.	O
</s>
<s>
To	O
prevent	O
errors	O
,	O
most	O
large	O
setext	B-Language
publications	O
are	O
created	O
using	O
a	O
markup	O
language	O
such	O
as	O
HTML	B-Language
or	O
SGML	O
and	O
then	O
converted	O
.	O
</s>
<s>
The	O
setext	B-Language
document	O
can	O
then	O
be	O
distributed	O
without	O
the	O
need	O
for	O
the	O
recipient	O
to	O
use	O
a	O
HTML	B-Language
email	O
or	O
web	O
viewer	O
.	O
</s>
<s>
Multiple	O
setext	B-Language
documents	O
can	O
be	O
stored	O
in	O
the	O
same	O
file	O
,	O
similarly	O
to	O
how	O
the	O
mbox	B-Application
format	O
can	O
store	O
multiple	O
e-mail	O
messages	O
together	O
.	O
</s>
<s>
It	O
was	O
initially	O
announced	O
that	O
multiple	O
documents	O
could	O
be	O
included	O
in	O
a	O
single	O
stream	O
,	O
separated	O
by	O
a	O
special	O
<end>	O
tag	O
serving	O
as	O
a	O
document	B-Algorithm
delimiter	I-Algorithm
.	O
</s>
<s>
After	O
several	O
months	O
,	O
it	O
was	O
clarified	O
that	O
this	O
tag	O
was	O
not	O
an	O
official	O
part	O
of	O
setext	B-Language
,	O
and	O
that	O
multiple	O
documents	O
should	O
instead	O
be	O
delimited	B-Algorithm
by	O
$$	O
appearing	O
at	O
the	O
end	O
of	O
a	O
line	O
of	O
text	O
.	O
</s>
<s>
The	O
following	O
are	O
the	O
ten	O
most	O
common	O
of	O
the	O
16	O
different	O
setext	B-Language
tags	O
.	O
</s>
<s>
==	O
==	O
==	O
==	O
==	O
==	O
==	O
==	O
==	O
==	O
A	O
distinct	O
title	O
identified	O
by	O
the	O
text	O
,	O
maximum	O
one	O
per	O
setext	B-Language
.	O
</s>
<s>
Next	O
paragraph	O
…	O
Lines	O
undented	O
and	O
unfolded	O
(	O
longer	O
lines	O
are	O
generally	O
tolerated	O
by	O
most	O
parsers	B-Language
)	O
.	O
</s>
<s>
href-tt	O
^	O
..	O
_hot_wordURL	O
^	O
..	O
_Wikipedia_home_page	O
https://wikipedia.org	O
(	O
Linked	O
in	O
the	O
text	O
with	O
a	O
hot-tt	O
as	O
Wikipedia_home_page_	O
)	O
These	O
'	O
link	O
definitions	O
 '	O
are	O
commonly	O
placed	O
at	O
the	O
end	O
of	O
a	O
paragraph/section	O
,	O
or	O
at	O
the	O
very	O
end	O
of	O
the	O
setext	B-Language
document	O
.	O
</s>
<s>
By	O
default	O
all	O
properly	O
setext-ized	O
files	O
will	O
have	O
an	O
"	O
.etx	O
"	O
or	O
"	O
.ETX	O
"	O
suffix	O
.	O
</s>
