What is DTD XML?

Related questions

1. Does XML indentation matter?
2. How does XML schema work?
3. Why XML is needed?
4. What is the alternative for XML and what are its advantages over XML?
5. What is whitespace in XML?
6. What is the real use of XML?
7. What is an XML schema file?
8. What are advantages of XML?
9. Can XML tags have spaces?
10. What is XML formatting?

Tags

1. #valid
2. #reference
3. #inside
4. #family
5. #blocks
6. #markup
7. #declarations
8. #definition
9. #language
10. #building
11. #declared
12. #external
13. #document
14. #inline
15. #define
16. #defines