Which tags does not require a closing tag?

Related questions

1. Which HTML tag has no end tag?
2. Why DIV tag is used in HTML?
3. What is &# in HTML?
4. What is the difference between BR tag and HR tag?
5. What are the basic HTML tags?
6. What is called in HTML?
7. What is span in HTML?
8. How do you do borders in HTML?
9. Why SPAN tag is used in HTML?
10. How do I add a border to a div in HTML?

Tags

1. #implied
2. #closing
3. #thead
4. #because
5. #colgroup
6. #started
7. #would
8. #tbody
9. #without
10. #however
11. #option
12. #tfoot
13. #following
14. #these
15. #optional