<s>
MECS	B-Language
is	O
the	O
Multi-Element	O
Code	O
System	O
,	O
a	O
markup	O
system	O
developed	O
by	O
the	O
Wittgenstein	O
Archives	O
at	O
the	O
University	O
of	O
Bergen	O
.	O
</s>
<s>
It	O
is	O
very	O
similar	O
to	O
SGML	B-Language
and	O
XML	B-Protocol
except	O
that	O
it	O
allows	O
elements	O
to	O
overlap	O
.	O
</s>
<s>
MECS	B-Language
supports	O
limited	O
overlap	O
,	O
in	O
that	O
a	O
given	O
type	O
of	O
element	O
(	O
for	O
example	O
a	O
quotation	O
)	O
,	O
may	O
overlap	O
other	O
types	O
,	O
but	O
no	O
element	O
may	O
overlap	O
another	O
of	O
the	O
same	O
type	O
.	O
</s>
<s>
MECS	B-Language
has	O
been	O
influential	O
in	O
the	O
theory	O
of	O
non-hierarchical	O
markup	O
systems	O
,	O
and	O
is	O
discussed	O
in	O
many	O
articles	O
by	O
Michael	O
Sperberg-McQueen	O
and	O
Claus	O
Huitfeldt	O
,	O
among	O
others	O
.	O
</s>
<s>
Other	O
systems	O
for	O
representing	O
overlapping	O
markup	O
include	O
the	O
Layered	O
Markup	O
and	O
Annotation	O
Language	O
,	O
CLIX	O
,	O
JITTS	O
,	O
EARMARK	O
and	O
features	O
of	O
the	O
Text	B-Language
Encoding	I-Language
Initiative	I-Language
and	O
the	O
Open	B-Language
Scripture	I-Language
Information	I-Language
Standard	I-Language
.	O
</s>
