19
ICH ICSR Implementation Guide 12 April 2013
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document follows the rules listed in the DTD, then the document is said to be valid.
SGML/XML documents that do not follow the rules in their DTDs are categorised as invalid.
The DTD specifies the required structure and format of a particular document.XML is more
flexible than SGML and allows for the concept of ‘well-formed’ data – content that meets the
basic vocabulary and ‘grammatical’ requirements of XML but does not reference a DTD for a
specific set of attributes or list of required elements.XML contains a further concept called a
schema. An XML schema introduces both the ability to apply more complex constraints and the
ability to have more flexibility in well-formed data.
In general, DTDs perform well when applied to documents or text-intensive information.XML
schema work best for data-intensive information5. One challenge with DTDs is that they
represent two different things at the same time: a grammar and a schema. Because XML syntax
is ‘fixed’, it does not need ‘grammar’ to properly access the information content. In addition,
XML schemas can be manipulated, stored, and indexed, which is a practical advantage6.
Another advantage to XML is that Unicode is universally present in all XML parsers. Except for
more recent ones, most SGML parsers do not provide Unicode support7. Unicode provides a
‘unique’ code (a number) for each character. Thus, characters are represented in an abstract way
while the visual rendering (size, shape, font or style) is left to other applications, such as a web
browser or word processor. In this way, translation between languages is built into the use of
XML8.
2.4.2.2 Advantages to Electronic Submissions
The ICH chose to adopt an XML schema for the ICSR as it is more suitable for the intended
purpose: XML is portable and non-proprietary. It can be used to store and share information
electronically across platforms. XML is used for encapsulating information to be passed
between two computing systems which might otherwise be unable to communicate. It provides
5Tittel, Ed, Pitts, Natanya, and Boumphrey, Frank.XML for Dummies. New York: Wiley
Publishing, Inc., 2002.
6‘Beyond the SGML DTD’, François CHAHUNEAU, Directeur Général/General Manager,
AIS S.A., 15-17 rue Rémy Dumoncel, 75014, Paris, FRANCE,
http://xml.coverpages.org/chahuneauXML.html
7‘XML: What HTML Wanted to Be!’, Norma Haakonstad, National Accounts Manager,
Arbortext, Inc., 1000 Victors Way, Ann Arbor (Michigan) 48108
8‘Unicode’.Wikipediahttp://en.wikipedia.org/wiki/Unicode, 18SEP2008.
ICH ICSR Implementation Guide 12 April 2013
-20-
document follows the rules listed in the DTD, then the document is said to be valid.
SGML/XML documents that do not follow the rules in their DTDs are categorised as invalid.
The DTD specifies the required structure and format of a particular document.XML is more
flexible than SGML and allows for the concept of ‘well-formed’ data – content that meets the
basic vocabulary and ‘grammatical’ requirements of XML but does not reference a DTD for a
specific set of attributes or list of required elements.XML contains a further concept called a
schema. An XML schema introduces both the ability to apply more complex constraints and the
ability to have more flexibility in well-formed data.
In general, DTDs perform well when applied to documents or text-intensive information.XML
schema work best for data-intensive information5. One challenge with DTDs is that they
represent two different things at the same time: a grammar and a schema. Because XML syntax
is ‘fixed’, it does not need ‘grammar’ to properly access the information content. In addition,
XML schemas can be manipulated, stored, and indexed, which is a practical advantage6.
Another advantage to XML is that Unicode is universally present in all XML parsers. Except for
more recent ones, most SGML parsers do not provide Unicode support7. Unicode provides a
‘unique’ code (a number) for each character. Thus, characters are represented in an abstract way
while the visual rendering (size, shape, font or style) is left to other applications, such as a web
browser or word processor. In this way, translation between languages is built into the use of
XML8.
2.4.2.2 Advantages to Electronic Submissions
The ICH chose to adopt an XML schema for the ICSR as it is more suitable for the intended
purpose: XML is portable and non-proprietary. It can be used to store and share information
electronically across platforms. XML is used for encapsulating information to be passed
between two computing systems which might otherwise be unable to communicate. It provides
5Tittel, Ed, Pitts, Natanya, and Boumphrey, Frank.XML for Dummies. New York: Wiley
Publishing, Inc., 2002.
6‘Beyond the SGML DTD’, François CHAHUNEAU, Directeur Général/General Manager,
AIS S.A., 15-17 rue Rémy Dumoncel, 75014, Paris, FRANCE,
http://xml.coverpages.org/chahuneauXML.html
7‘XML: What HTML Wanted to Be!’, Norma Haakonstad, National Accounts Manager,
Arbortext, Inc., 1000 Victors Way, Ann Arbor (Michigan) 48108
8‘Unicode’.Wikipediahttp://en.wikipedia.org/wiki/Unicode, 18SEP2008.