Investor's Checklist: Rules for successful stock investing

I am reading The Five Rules for Successful Stock Investing: Morningstar's Guide to Building Wealth and Winning...By Pat Dorsey at the moment. I found the following checklist on the page 11.

1. Have a personal discipline, do not listen crowds. It is therefore crucial to have solid well-grounded investment philosopy.
2. Do not buy a stock unless you understand their business.
3. Look for companies with compatitive advantage.
4. Do not buy a stock without a margin of safety.
5. Buy and hold stocks for the long term.
6. Know when to sell. For example sell when it exceeds its instrinsic value.