<s>
Schematron	B-Language
is	O
a	O
rule-based	O
validation	B-Language
language	O
for	O
making	O
assertions	O
about	O
the	O
presence	O
or	O
absence	O
of	O
patterns	O
in	O
XML	B-Protocol
trees	O
.	O
</s>
<s>
It	O
is	O
a	O
structural	O
schema	O
language	O
expressed	O
in	O
XML	B-Protocol
using	O
a	O
small	O
number	O
of	O
elements	O
and	O
XPath	B-Language
.	O
</s>
<s>
In	O
many	O
implementations	O
,	O
the	O
Schematron	B-Language
schema	O
XML	B-Protocol
is	O
processed	O
into	O
normal	O
XSLT	B-Application
code	O
for	O
deployment	O
anywhere	O
that	O
XSLT	B-Application
can	O
be	O
used	O
.	O
</s>
<s>
Schematron	B-Language
is	O
capable	O
of	O
expressing	O
constraints	O
in	O
ways	O
that	O
other	O
XML	B-Protocol
schema	O
languages	O
like	O
XML	B-Protocol
Schema	O
and	O
DTD	B-Language
cannot	O
.	O
</s>
<s>
Schematron	B-Language
can	O
also	O
specify	O
required	O
relationships	O
between	O
multiple	O
XML	B-Protocol
files	O
.	O
</s>
<s>
Constraints	O
and	O
content	O
rules	O
may	O
be	O
associated	O
with	O
"	O
plain-English	O
"	O
(	O
or	O
any	O
language	O
)	O
validation	B-Language
error	O
messages	O
,	O
allowing	O
translation	O
of	O
numeric	O
Schematron	B-Language
error	O
codes	O
into	O
meaningful	O
user	O
error	O
messages	O
.	O
</s>
<s>
The	O
current	O
ISO	O
recommendation	O
is	O
Information	O
technology	O
,	O
Document	B-Language
Schema	I-Language
Definition	I-Language
Languages	I-Language
(	O
DSDL	B-Language
)	O
,	O
Part	O
3	O
:	O
Rule-based	O
validation	B-Language
,	O
Schematron	B-Language
(	O
ISO/IEC	O
19757-3:2020	O
)	O
.	O
</s>
<s>
Constraints	O
are	O
specified	O
in	O
Schematron	B-Language
using	O
an	O
XPath-based	O
language	O
that	O
can	O
be	O
deployed	O
as	O
XSLT	B-Application
code	O
,	O
making	O
it	O
practical	O
for	O
applications	O
such	O
as	O
the	O
following	O
:	O
</s>
<s>
Adjunct	O
to	O
Structural	O
Validation	B-Language
By	O
testing	O
for	O
co-occurrence	O
constraints	O
,	O
non-regular	O
constraints	O
,	O
and	O
inter-document	O
constraints	O
,	O
Schematron	B-Language
can	O
extend	O
the	O
validations	O
that	O
can	O
be	O
expressed	O
in	O
languages	O
such	O
as	O
DTDs	O
,	O
RELAX	B-Language
NG	I-Language
or	O
XML	B-Protocol
Schema	O
.	O
</s>
<s>
Lightweight	O
Business	O
Rules	O
Engine	O
Schematron	B-Language
is	O
not	O
a	O
comprehensive	O
,	O
Rete	B-Algorithm
rules	O
engine	O
,	O
but	O
it	O
can	O
be	O
used	O
to	O
express	O
rules	O
about	O
complex	O
structures	O
with	O
an	O
XML	B-Protocol
document	I-Protocol
.	O
</s>
<s>
XML	B-Protocol
Editor	O
Syntax	O
Highlighting	O
Rules	O
Some	O
XML	B-Protocol
editors	O
use	O
Schematron	B-Language
rules	O
to	O
conditionally	O
highlight	O
XML	B-Protocol
files	O
for	O
errors	O
.	O
</s>
<s>
Not	O
all	O
XML	B-Protocol
editors	O
support	O
Schematron	B-Language
.	O
</s>
<s>
Schematron	B-Language
was	O
invented	O
by	O
Rick	O
Jelliffe	O
while	O
at	O
Academia	O
Sinica	O
Computing	O
Centre	O
,	O
Taiwan	O
.	O
</s>
<s>
He	O
described	O
Schematron	B-Language
as	O
"	O
a	O
feather	O
duster	O
to	O
reach	O
the	O
parts	O
other	O
schema	O
languages	O
cannot	O
reach	O
"	O
.	O
</s>
<s>
The	O
most	O
common	O
versions	O
of	O
Schematron	B-Language
are	O
:	O
</s>
<s>
Schematron	B-Language
1.3	O
(	O
2000	O
)	O
:	O
This	O
version	O
used	O
the	O
namespace	O
http://xml.ascc.net/schematron/	O
.	O
</s>
<s>
It	O
was	O
supported	O
by	O
an	O
XSLT	B-Application
implementation	O
with	O
a	O
plug-in	O
architecture	O
.	O
</s>
<s>
(	O
2002	O
)	O
:	O
This	O
version	O
was	O
the	O
base	O
of	O
ISO	O
Schematron	B-Language
and	O
obsoleted	O
by	O
it	O
.	O
</s>
<s>
(	O
2006	O
)	O
:	O
This	O
version	O
regularizes	O
several	O
features	O
,	O
and	O
provides	O
an	O
XML	B-Protocol
output	O
format	O
,	O
Schematron	B-Language
Validation	B-Language
Report	O
Language	O
(	O
SVRL	O
)	O
.	O
</s>
<s>
It	O
uses	O
the	O
new	O
namespace	O
http://purl.oclc.org/dsdl/schematron	O
.	O
</s>
<s>
ISO	O
Schematron	B-Language
(	O
2010	O
)	O
:	O
This	O
version	O
added	O
support	O
for	O
XSLT2	O
.	O
</s>
<s>
ISO	O
Schematron	B-Language
(	O
2016	O
)	O
:	O
</s>
<s>
ISO	O
Schematron	B-Language
(	O
2020	O
)	O
:	O
This	O
version	O
added	O
support	O
for	O
XSLT3	O
.	O
</s>
<s>
Schematron	B-Language
has	O
been	O
standardized	O
by	O
the	O
ISO	O
as	O
Information	O
technology	O
,	O
Document	B-Language
Schema	I-Language
Definition	I-Language
Languages	I-Language
(	O
DSDL	B-Language
)	O
,	O
Part	O
3	O
:	O
Rule-based	O
validation	B-Language
,	O
Schematron	B-Language
(	O
ISO/IEC	O
19757-3:2020	O
)	O
.	O
</s>
<s>
Schematron	B-Language
rules	O
can	O
be	O
created	O
using	O
a	O
standard	O
XML	B-Protocol
editor	O
or	O
XForms	B-Application
application	O
.	O
</s>
<s>
This	O
rule	O
checks	O
to	O
make	O
sure	O
that	O
the	O
XML	B-Protocol
element	O
has	O
a	O
date	O
that	O
is	O
before	O
the	O
current	O
date	O
.	O
</s>
<s>
If	O
this	O
rule	O
fails	O
the	O
validation	B-Language
will	O
fail	O
and	O
an	O
error	O
message	O
which	O
is	O
the	O
body	O
of	O
the	O
assert	O
element	O
will	O
be	O
returned	O
to	O
the	O
user	O
.	O
</s>
<s>
Schematron	B-Language
schemas	O
are	O
suitable	O
for	O
use	O
in	O
XML	B-Operating_System
Pipelines	I-Operating_System
,	O
thereby	O
allowing	O
workflow	O
process	O
designers	O
to	O
build	O
and	O
maintain	O
rules	O
using	O
XML	B-Protocol
manipulation	O
tools	O
.	O
</s>
<s>
The	O
W3C	O
's	O
XProc	B-Language
pipelining	O
language	O
,	O
for	O
example	O
,	O
has	O
native	O
support	O
for	O
Schematron	B-Language
schema	O
processing	O
through	O
its	O
"	O
validate-with-schematron	O
"	O
step	O
.	O
</s>
<s>
Since	O
Schematron	B-Language
schemas	O
can	O
be	O
transformed	O
into	O
XSLT	B-Application
stylesheets	O
,	O
these	O
can	O
themselves	O
be	O
used	O
in	O
XML	B-Operating_System
Pipelines	I-Operating_System
which	O
support	O
XSLT	B-Application
transformation	O
.	O
</s>
<s>
An	O
Apache	B-Application
Ant	I-Application
task	O
can	O
be	O
used	O
to	O
convert	O
Schematron	B-Language
rules	O
into	O
XSLT	B-Application
files	O
.	O
</s>
<s>
There	O
exists	O
also	O
native	O
Schematron	B-Language
implementation	O
,	O
like	O
the	O
Java	O
implementation	O
from	O
Innovimax/INRIA	O
,	O
,	O
that	O
also	O
do	O
streaming	B-Language
.	O
</s>
