Know-how can include any information that provides competitive advantage. For example, a rapidly-accessible database of current telephone numbers and addresses enables telephone companies to extract $0.50, $0.99, or more from callers to "Information" or "411".

Trade secrets, which are a particular form of Know-how, are not generally known, and are maintained via reasonable measures of security.  For example, trade secrets can include:

• Customer lists and data
• Marketing methods
• Formulas and manufacturing processes
• Software code
• Accounting, trading, & brokerage processes
• Proprietary business information

Note that, absent a contract, you have no right to exclude others from using "proper means" to obtain what you consider to be your know-how or trade secret.

Proper means can include independent development, reverse engineering, obtaining from a third party who has a right to provide, or obtaining from you without breaching a contractual or other duty.

Improper means can involve breach of contract, espionage, theft, fraud, bribery, coercion, etc.

Trade secrets are often protected by Non-Disclosure and/or Employment Agreements, employee training, physical security, and/or other well-managed security practices. Nevertheless, trade secrets frequently fall into the public domain. Thus, many trade secret holders consider patent protection when feasible.