24 CFR §881.101

1. (a)The purpose of the Section 8 program is to provide low-income families with decent, safe and sanitary rental housing through the use of a system of housing assistance payments. This part contains the policies and procedures applicable to the Section 8 substantial rehabilitation program. The assistance may be provided to public housing agency owners or to private owners either directly from HUD or through public housing agencies.
2. (b)This part does not apply to projects developed under other Section 8 program regulations, including 24 CFR parts 880, 882, 883, 884, and 885, except to the extent specifically stated in those parts.