Protective classes include:
Title VIII of the Civil Rights Act of 1968, the Fair Housing Act was passed by Congress four days after the assassination of Martin Luther King, Jr. This legislation prohibits discrimination by direct providers of housing (landlords and real estate companies) as well as other entities (such as municipalities, banks and other lending institutions, and homeowners insurance companies). Discrimination in other housing-related activities such as advertising, zoning practices, and new construction design is also covered. As a result of this legislation, the practices of redlining and the writing of racially restrictive covenants into deeds were deemed illegal.
When originally passed in 1968, the Fair Housing Act only covered four protective classes: race, color, religion, and national origin https://www.bostonfairhousing.org/payday-loans.html. Sex was added as a protective class in 1974. In 1988, disability and familial status were included as protective classes as well.