Opt-ins: owner made an active decision to renew project-based Section 8 rental contract
Opt-outs: owner made an active decision to stop renewal of project based Section 8 rental contract
Source: U.S. Department of Housing and Urban Development. (2015). Opting in, Opting Out a Decade Later. Retrieved from: http://www.huduser.org/portal/publications/mdrt/opting_in_opting_out.html