Even if you are exempt from HMDA, Regulation B will still apply to certain transactions. The Reg B monitoring info rules states in 12 CFR 1002.13:
A creditor that receives an application for credit primarily for the purchase or refinancing of a dwelling occupied or to be occupied by the applicant as a principal residence, where the extension of credit will be secured by the dwelling, shall request as part of the application the following information regarding the applicant(s):
(i) Ethnicity and race using either:
(A) For ethnicity, the aggregate categories Hispanic or Latino and not Hispanic or Latino; and, for race, the aggregate categories American Indian or Alaska Native, Asian, Black or African American, Native Hawaiian or Other Pacific Islander, and White; or
(B) The categories and subcategories for the collection of ethnicity and race set forth in appendix B to 12 CFR part 1003.
(ii) Sex;
(iii) Marital status, using the categories married, unmarried, and separated; and
(iv) Age
Certain institutions (including those who were or will likely be HMDA reporters) may also collect information under other limited circumstances. You can find that in 1002.5(a) – look at (a)(4) in particular regarding voluntary Reg C reporting, if you reporting HMDA info in the last five year, or if you may be reporting such info in the future.
Please let us know if you have any follow-up questions.