Title VII of the Civil Rights Act of 1964: Federal law prohibiting discrimination in recommendation letters based on race, color, religion, sex, or national origin. Letters should avoid references to these protected characteristics.

Americans with Disabilities Act (ADA): Federal law protecting individuals with disabilities from discrimination. Recommendation letters should not disclose disability information or discriminate based on disability status.

Age Discrimination in Employment Act (ADEA): Federal law protecting individuals 40 and older from age discrimination. References to age should be avoided in recommendation letters.

State Defamation Laws: State-specific laws governing libel and slander. All statements in recommendation letters must be truthful and verifiable to avoid potential defamation claims.

Family Educational Rights and Privacy Act (FERPA): Federal law protecting the privacy of student education records. Relevant when including educational information in recommendation letters.

State Privacy Laws: Various state-specific laws governing the protection and disclosure of personal information in employment contexts.

State Employment Reference Laws: State-specific regulations governing what information can be shared about former employees in reference letters, including 'good faith' provisions.

Company Reference Policies: Internal organizational policies governing the issuance of recommendation letters, including restrictions on content and authorization requirements.