An implementation may only find a document-type definition for a public identifier when the identifier is encountered. Public identifiers are strictly assigned and distributed with the document type definition. The public identifier system was established to minimize the possibility of having different DTD files for the same document-type definition. The document-type definition of the XML document shall be parsed for tags and attributes. This method is compatible with both the DTD and XML Schema specifications.
All tags are to be collected and sorted alphabetically with no hierarchy information.
Tags are associated with values up to and including 0x3F . This encoding supports 58 tags. Associating Attribute Names and Attribute Values Like tags, account for all attribute names. If the attributes have given values, the each attribute name and value should be a separate entry. 0x80 through 0x8F are reserved and defined in section 7.2.