If items aren t properly nested, it s no big deal to the browsers. But in XML, an improperly formatted file creates a fatal error. Applications will refuse to process the file. That means a document must be what XML experts call well-formed to work right. It has to be ready for a computer program to read, and thus ready to be used in multiple ways for network delivery.
Empty tags use the special XML syntax .
All the entities, or reusable data chunks, are declared. Checking for code errors across thousands of documents is tough, so XML users turn to automated tools such as the Lark parser. XML designers recognized that document authors sometimes omit important information or include extraneous text. The document type definition, or DTD, makes sure that XML coding will do what was intended. The root element contains all other elements. .