Laura and Al Ries wrote The 22 Immutable Laws of Branding in 2002. Highlights:

1. The Law of Expansion: The power of a brand is inversely proportional to its scope. Trying to be all things to all people undermines the power of the brand.

2. The Law of Contraction: A brand becomes stronger when you narrow its focus. By narrowing the focus to a single category, a brand can achieve extraordinary success.

3. The Law of Publicity: The birth of a brand is achieved with publicity, not advertising. A new brand must be capable of generating favorable public-ity in the media or it won’t have a chance in the marketplace.

4. The Law of Advertising: Once born, a brand needs advertising to stay healthy. Sooner or later, a brand leader has to shift its branding strategy from publicity to advertising.

5. The Law of the Word: A brand should strive to own a word in the mind of the consumer. If you want to build a brand, you must focus your branding efforts on owning a word in the prospect’s mind.

6. The Law of Credentials: The crucial ingredient in the success of any brand is its claim to authenticity. Coke is the real thing in the minds of many, even though the last 'real thing' advertisement ran almost thirty years ago.

7. The Law of Quality: Quality is important, but brands are not built by quality alone. Does a Rolex keep better time than a Timex?

8. The Law of the Category: A leading brand should promote the category, not the brand. The most efficient, most productive, most useful aspect of branding is creating a new category.

9. The Law of the Name: In the long run, a brand is nothing more than a name. In the short term, a brand needs a unique idea or concept to survive.

10. The Law of Extensions: The easiest way to destroy a brand is to put its name on everything. More than 90% of all new product introductions in the U.S. are line extensions. Line extensions destroy brand value by weakening the brand.

11. The Law of Fellowship: In order to build the category, a brand should welcome other brands. Consumers want to have choices. Choice stimulates demand. Healthy competition helps to build the category.

12. The Law of the Generic: One of the fastest routes to failure is giving a brand a generic name. The problem with a generic brand name is its inability to differentiate the brand from the competition.

13. The Law of the Company: Brands are brands. Companies are companies. There is a difference. Customer’s think of brands, not companies.

14. The Law of Subbrands: What branding builds, subbranding can destroy. Subbranding erodes the power of the core brand.

15. The Law of Siblings: There is a time and place to launch a second brand. A second brand can be launched to focus on a new subcategory within the same product family.

16. The Law of Shape: A brand’s logotype should be designed to fit the eyes. Both eyes. A customer sees the world through two horizontal-ly mounted eyes peering out of the head. For maximum visual impact, a logotype should have a horizontal shape. The ideal shape is 2 1 /4 units wide by 1 unit high.

17. The Law of Color: A brand should use a color that is the opposite of its major competitor. Coke is red, and Pepsi is Blue. Hertz is yellow, and Avis is Red. Color consistency over the long term can help a brand burn its way into the mind.

18. The Law of Borders: There are no barriers to global branding. A brand should know no borders. The perfect solution to growth in a competitive market is not line extensions, but building a global brand. A brand should have a consistent message globally, but must take into account the perceptions of its country of origin.

19. The Law of Consistency: A brand is not built overnight. Success is measured in decades, not years.This is the law which is violated most frequently.

20. The Law of Change: Brands can be changed, but only infrequently and only very carefully. Nothing is absolute and there are exceptions to every rule. There are three situations where changing your brand is feasible: When your brand is weak or non-existent in the mind, when you want to move your brand down the food chain to a lower price and perception point, or when your brand is in a slow-moving field and the change is going to take place over an extended period of time. Remember, changing your brand is a long and difficult process. Change at your own risk!

21. The Law of Mortality: No brand will live forever. Euthanasia is often thebest solution. While the laws of branding are immutable, brands themselves are not. They are born, grow up, mature, and eventually will die. Yet companies that are willing to spend millions to save a dying brand, won’t spend pennies to launch a new one. Opportunities for new brands and threats to old ones are constantly being created by the invention of new categories. The rise of personal computers created opportunities for Compaq, Dell and Gateway, but put pressure on Digital, Data General and Wang.

22. The Law of Singularity: The most important aspect of a brand is its single-mindedness. What is a brand? A singular idea or concept that you own inside the mind of the prospect. It’s as simple or as difficult as that.

More:
1. Generate publicity, not advertising. Best way to get publicity? Announce a new category, not a new product.
2. Claim your product is a "leader", not "better". All products claim they are better, but you can’t argue with leader.
3. Own a word. Like "luxury".
4. Perception of quality is built by a narrowly focused brand, a high price, and a better name.
5. Promote the category, not the brand, and be first in the category so that your brand is associated with the category.
6. Expand a brand, reduce its power. Contract a brand, increase its power.
7. Welcome other brands in order to build the category.
8. Generic brand name = bad
9. Select a brand color opposite of that of your main competitor’s.
10. Consistency is key. Never change your brand, ever.
11. What’s a brand? A proper noun that can be used in place of a word.

[From the Great Books  Series. Also see The Success Manual  - Encyclopedia of Advice, which contains summaries of 100+ Most useful books.]