24 C.F.R. § 100.90

(a) It shall be unlawful to deny any person access to or membership or participation in any multiple listing service, real estate brokers' organization or other service, organization, or facility relating to the business of selling or renting dwellings, or to discriminate against any person in the terms or conditions of such access, membership or participation, because of race, color, religion, sex, handicap, familial status, or national origin.

(b) Prohibited actions under this section include, but are not limited to:

(1) Setting different fees for access to or membership in a multiple listing service because of race, color, religion, sex, handicap, familial status, or national origin.

(2) Denying or limiting benefits accruing to members in a real estate brokers' organization because of race, color, religion, sex, handicap, familial status, or national origin.

(3) Imposing different standards or criteria for membership in a real estate sales or rental organization because of race, color, religion, sex, handicap, familial status, or national origin.

(4) Establishing geographic boundaries or office location or residence requirements for access to or membership or participation in any multiple listing service, real estate brokers' organization or other service, organization or facility relating to the business of selling or renting dwellings, because of race, color, religion, sex, handicap, familial status, or national origin.

(5) Conditioning access to brokerage services on a person's response to harassment because of race, color, religion, sex, handicap, familial status, or national origin.

(6) Subjecting a person to harassment because of race, color, religion, sex, handicap, familial status, or national origin that has the effect of discouraging or denying access to brokerage services.