I think @tagteam 's summary is correct. From US Code 280A:
(2)Personal use of unit: For purposes of this section, the taxpayer shall be deemed to have used a dwelling unit for personal purposes for a day if, for any part of such day, the unit is used—
(A)
for personal purposes by the taxpayer or any other person who has an interest in such unit, or by any member of the family (as defined in section 267(c)(4)) of the taxpayer or such other person.
Also, this HUD website allows you to look up fair market rents by zip code:
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
