<s>
A	O
topic	B-Application
map	I-Application
is	O
a	O
standard	O
for	O
the	O
representation	O
and	O
interchange	O
of	O
knowledge	O
,	O
with	O
an	O
emphasis	O
on	O
the	O
findability	O
of	O
information	O
.	O
</s>
<s>
Topic	B-Application
maps	I-Application
were	O
originally	O
developed	O
in	O
the	O
late	O
1990s	O
as	O
a	O
way	O
to	O
represent	O
back-of-the-book	O
index	O
structures	O
so	O
that	O
multiple	O
indexes	O
from	O
different	O
sources	O
could	O
be	O
merged	O
.	O
</s>
<s>
The	O
ISO/IEC	O
standard	O
is	O
formally	O
known	O
as	O
ISO/IEC	B-Application
13250:2003	I-Application
.	O
</s>
<s>
Topic	B-Application
maps	I-Application
are	O
similar	O
to	O
concept	O
maps	O
and	O
mind	O
maps	O
in	O
many	O
respects	O
,	O
though	O
only	O
topic	B-Application
maps	I-Application
are	O
ISO	O
standards	O
.	O
</s>
<s>
Topic	B-Application
maps	I-Application
are	O
a	O
form	O
of	O
semantic	O
web	O
technology	O
similar	O
to	O
RDF	O
.	O
</s>
<s>
The	O
definitions	O
of	O
allowed	O
types	O
is	O
known	O
as	O
the	O
ontology	O
of	O
the	O
topic	B-Application
map	I-Application
.	O
</s>
<s>
Topic	B-Application
maps	I-Application
explicitly	O
support	O
the	O
concept	O
of	O
merging	O
of	O
identity	O
between	O
multiple	O
topics	O
or	O
topic	B-Application
maps	I-Application
.	O
</s>
<s>
Furthermore	O
,	O
because	O
ontologies	O
are	O
topic	B-Application
maps	I-Application
themselves	O
,	O
they	O
can	O
also	O
be	O
merged	O
thus	O
allowing	O
for	O
the	O
automated	O
integration	O
of	O
information	O
from	O
diverse	O
sources	O
into	O
a	O
coherent	O
new	O
topic	B-Application
map	I-Application
.	O
</s>
<s>
Features	O
such	O
as	O
subject	O
identifiers	O
(	O
URIs	B-Protocol
given	O
to	O
topics	O
)	O
and	O
PSIs	O
(	O
published	O
subject	O
indicators	O
)	O
are	O
used	O
to	O
control	O
merging	O
between	O
differing	O
taxonomies	O
.	O
</s>
<s>
The	O
work	O
standardizing	O
topic	B-Application
maps	I-Application
(	O
ISO/IEC	B-Application
13250	I-Application
)	O
took	O
place	O
under	O
the	O
umbrella	O
of	O
the	O
ISO/IEC	O
JTC	O
1/SC	O
34/WG	O
3	O
committee	O
(	O
ISO/IEC	O
Joint	O
Technical	O
Committee	O
1	O
,	O
Subcommittee	O
34	O
,	O
Working	O
Group	O
3	O
–	O
Document	O
description	O
and	O
processing	O
languages	O
–	O
Information	O
Association	O
)	O
.	O
</s>
<s>
However	O
,	O
WG3	O
was	O
disbanded	O
and	O
maintenance	O
of	O
ISO/IEC	B-Application
13250	I-Application
was	O
assigned	O
to	O
WG8	O
.	O
</s>
<s>
The	O
topic	B-Application
maps	I-Application
(	O
ISO/IEC	B-Application
13250	I-Application
)	O
reference	O
model	O
and	O
data	O
model	O
standards	O
are	O
defined	O
independent	O
of	O
any	O
specific	O
serialization	O
or	O
syntax	O
.	O
</s>
<s>
In	O
2000	O
,	O
Topic	B-Application
Maps	I-Application
was	O
defined	O
in	O
an	O
XML	O
syntax	O
XTM	O
.	O
</s>
<s>
Note	O
that	O
XTM	O
1.0	O
predates	O
and	O
therefore	O
is	O
not	O
compatible	O
with	O
the	O
more	O
recent	O
versions	O
of	O
the	O
(	O
ISO/IEC	B-Application
13250	I-Application
)	O
standard	O
.	O
</s>
<s>
The	O
above	O
standards	O
are	O
all	O
recently	O
proposed	O
or	O
defined	O
as	O
part	O
of	O
ISO/IEC	B-Application
13250	I-Application
.	O
</s>
<s>
Linear	O
topic	B-Application
map	I-Application
notation	O
(	O
LTM	O
)	O
serves	O
as	O
a	O
kind	O
of	O
shorthand	O
for	O
writing	O
topic	B-Application
maps	I-Application
in	O
plain	O
text	O
editors	O
.	O
</s>
<s>
This	O
is	O
useful	O
for	O
writing	O
short	O
personal	O
topic	B-Application
maps	I-Application
or	O
exchanging	O
partial	O
topic	B-Application
maps	I-Application
by	O
email	O
.	O
</s>
<s>
When	O
writing	O
topic	B-Application
maps	I-Application
manually	O
it	O
is	O
much	O
more	O
compact	O
,	O
but	O
of	O
course	O
can	O
be	O
converted	O
to	O
XTM	O
.	O
</s>
<s>
Alternatively	O
,	O
it	O
can	O
be	O
used	O
directly	O
with	O
the	O
Perl	B-Language
Module	O
TM	O
(	O
which	O
also	O
supports	O
LTM	O
)	O
.	O
</s>
<s>
A	O
de	O
facto	O
API	B-Application
standard	O
called	O
Common	O
Topic	B-Application
Maps	I-Application
Application	B-Application
Programming	I-Application
Interface	I-Application
(	O
TMAPI	O
)	O
was	O
published	O
in	O
April	O
2004	O
and	O
is	O
supported	O
by	O
many	O
Topic	B-Application
Maps	I-Application
implementations	O
or	O
vendors	O
:	O
</s>
<s>
In	O
normal	O
use	O
it	O
is	O
often	O
desirable	O
to	O
have	O
a	O
way	O
to	O
arbitrarily	O
query	O
the	O
data	O
within	O
a	O
particular	O
Topic	B-Application
Maps	I-Application
store	O
.	O
</s>
<s>
Many	O
implementations	O
provide	O
a	O
syntax	O
by	O
which	O
this	O
can	O
be	O
achieved	O
(	O
somewhat	O
like	O
'	O
SQL	O
for	O
Topic	B-Application
Maps	I-Application
 '	O
)	O
but	O
the	O
syntax	O
tends	O
to	O
vary	O
a	O
lot	O
between	O
different	O
implementations	O
.	O
</s>
<s>
With	O
this	O
in	O
mind	O
,	O
work	O
has	O
gone	O
into	O
defining	O
a	O
standardized	O
syntax	O
for	O
querying	O
topic	B-Application
maps	I-Application
:	O
</s>
<s>
It	O
can	O
also	O
be	O
desirable	O
to	O
define	O
a	O
set	O
of	O
constraints	O
that	O
can	O
be	O
used	O
to	O
guarantee	O
or	O
check	O
the	O
semantic	O
validity	O
of	O
topic	B-Application
maps	I-Application
data	O
for	O
a	O
particular	O
domain	O
.	O
</s>
<s>
(	O
Somewhat	O
like	O
database	O
constraints	O
for	O
topic	B-Application
maps	I-Application
)	O
.	O
</s>
<s>
TMCL	O
is	O
functionally	O
similar	O
to	O
RDF	O
Schema	O
with	O
Web	B-Language
Ontology	I-Language
Language	I-Language
(	O
OWL	B-Language
)	O
.	O
</s>
<s>
The	O
"	O
Topic	B-Application
Maps	I-Application
"	O
concept	O
has	O
existed	O
for	O
a	O
long	O
time	O
.	O
</s>
<s>
More	O
information	O
about	O
such	O
standards	O
can	O
be	O
found	O
at	O
the	O
ISO	O
Topic	B-Application
Maps	I-Application
site	O
.	O
</s>
<s>
Some	O
work	O
has	O
been	O
undertaken	O
to	O
provide	O
interoperability	O
between	O
the	O
W3C	O
's	O
RDF/OWL/SPARQL	O
family	O
of	O
semantic	O
web	O
standards	O
and	O
the	O
ISO	O
's	O
family	O
of	O
Topic	B-Application
Maps	I-Application
standards	O
though	O
the	O
two	O
have	O
slightly	O
different	O
goals	O
.	O
</s>
<s>
The	O
semantic	O
expressive	B-Language
power	I-Language
of	O
Topic	B-Application
Maps	I-Application
is	O
,	O
in	O
many	O
ways	O
,	O
equivalent	O
to	O
that	O
of	O
RDF	O
,	O
but	O
the	O
major	O
differences	O
are	O
that	O
Topic	B-Application
Maps	I-Application
(	O
i	O
)	O
provide	O
a	O
higher	O
level	O
of	O
semantic	O
abstraction	O
(	O
providing	O
a	O
template	O
of	O
topics	O
,	O
associations	O
and	O
occurrences	O
,	O
while	O
RDF	O
only	O
provides	O
a	O
template	O
of	O
two	O
arguments	O
linked	O
by	O
one	O
relationship	O
)	O
and	O
(	O
hence	O
)	O
(	O
ii	O
)	O
allow	O
n-ary	O
relationships	O
(	O
hypergraphs	O
)	O
between	O
any	O
number	O
of	O
nodes	O
,	O
while	O
RDF	O
is	O
limited	O
to	O
triplets	O
.	O
</s>
