24 C.F.R. § 100.141
As used in this subpart:
Lender means a person who engages in a residential real estate-related lending transaction.
Residential real estate-related lending transaction means the making of a loan:
Self-test means any program, practice or study a lender voluntarily conducts or authorizes which is designed and used specifically to determine the extent or effectiveness of compliance with the Fair Housing Act. The self-test must create data or factual information that is not available and cannot be derived from loan files, application files, or other residential real estate-related lending transaction records. Self-testing includes, but is not limited to, using fictitious credit applicants (testers) or conducting surveys of applicants or customers, nor is it limited to the pre-application stage of loan processing.
24 C.F.R. §100.141