There are two levels of conformance in the XML specifications: a well-formed and a valid message.
A well-formed message is an XML document that conforms to the structural rules of XML:
The first line should be the XML document declaration
The document should contain at least one element (or tag)
Every starting tag should have a closing tag
Self-closing tags (for example, '<tag/>') are permitted when XML elements do not contain data
Tags cannot overlap.
In addition, as XML is case sensitive, all the fields and attribute names have to be in lower case in order to comply with the XML DTD.
A Valid XML file is one, which has a DTD reference and which conforms to the ICH ICSR DTD and the TGA ICSR business rules.
The ICH ICSR DTD defines the valid elements (tags), attributes that may appear in a particular type of XML document and also defines element nesting rules.
The following XML special characters (excluding quotation marks) ">", "<" and "&" when occurring in text should always be replaced by ">" "<" and "&" respectively. Regarding all aspects of XML, the W3C standards should be followed.
