From HUD:
Questions and Answers Concerning the Final Rule Implementing
the Housing for Older Persons Act of 1995 (HOPA)
Title VIII of the Civil Rights Act of 1968 (the Federal Fair Housing Act), as amended by the Fair Housing Amendments Act of 1988 (the Fair Housing Act), prohibits discrimination in housing and real estate-related transactions based on race, color, religion, sex, national origin, handicap
and familial status (in general, the presence of children under the age of 18 in the household). The prohibition against discrimination based on familial status became effective March 12, 1989.
The Act contained a provision exempting "senior" housing from the prohibition against familial status discrimination.
The Housing for Older Persons Act
(HOPA), signed into law by President Clinton on December 28, 1995,
amended the housing for older persons exemption against familial status discrimination. The HOPA modified the statutory definition of housing for older persons as housing intended and operated for occupancy by at least one person 55 years of age or older per unit........"
http://portal.hud.gov/hudportal/docu...d=DOC_7769.pdf