<s>
XOXO	B-General_Concept
(	O
eXtensible	O
Open	O
XHTML	B-Language
Outlines	O
)	O
for	O
web	O
syndication	O
is	O
an	O
XML	B-Protocol
microformat	B-General_Concept
for	O
outlines	O
built	O
on	O
top	O
of	O
XHTML	B-Language
.	O
</s>
<s>
Developed	O
by	O
several	O
authors	O
as	O
an	O
attempt	O
to	O
reuse	O
XHTML	B-Language
building	O
blocks	O
instead	O
of	O
inventing	O
unnecessary	O
new	O
XML	B-Protocol
elements/attributes	O
,	O
XOXO	B-General_Concept
is	O
based	O
on	O
existing	O
conventions	O
for	O
publishing	O
outlines	O
,	O
lists	O
,	O
and	O
blogrolls	O
on	O
the	O
Web	O
.	O
</s>
<s>
The	O
XOXO	B-General_Concept
specification	O
defines	O
an	O
outline	O
as	O
a	O
hierarchical	O
,	O
ordered	O
list	O
of	O
arbitrary	O
elements	O
.	O
</s>
<s>
the	O
more	O
semantic	O
version	O
of	O
the	O
S5	B-Application
presentation	I-Application
file	I-Application
format	I-Application
is	O
based	O
upon	O
XOXO	B-General_Concept
.	O
</s>
<s>
The	O
XML	B-Protocol
elements	O
in	O
an	O
XOXO	B-General_Concept
document	O
are	O
:	O
</s>
<s>
The	O
ordered	O
list	O
and	O
unordered	O
list	O
are	O
the	O
root	O
elements	O
of	O
XOXO	B-General_Concept
.	O
</s>
<s>
They	O
may	O
contain	O
the	O
class	O
attribute	O
with	O
the	O
value	O
xoxo	B-General_Concept
.	O
</s>
<s>
Possible	O
attributes	O
include	O
:	O
a	O
title	O
attribute	O
to	O
indicate	O
additional	O
information	O
;	O
a	O
type	O
attribute	O
to	O
indicate	O
the	O
MIME	B-Application
type	I-Application
of	O
the	O
link	O
destination	O
;	O
a	O
rel	O
attribute	O
to	O
indicate	O
the	O
link	O
resource	O
’s	O
relationship	O
to	O
this	O
outline	O
(	O
e.g.	O
</s>
<s>
using	O
XFN	B-General_Concept
)	O
;	O
and/or	O
a	O
rev	O
attribute	O
to	O
indicate	O
the	O
relationship	O
of	O
this	O
outline	O
to	O
the	O
linked	O
resource	O
(	O
e.g.	O
</s>
