@sjrcpa  This turns out to be just another "trick the IRS computer" question.  IRS Pub 527 advises, 

"Used as a home but rented less than 15 days. If you use a dwelling unit as a home and you rent it less than 15 days during the year, its primary function isn’t considered to be rental and it shouldn’t be reported on Schedule E (Form 1040). You aren’t required to report the rental income and rental expenses from this activity."

But there is no corresponding box on the 1099-MISC for the payer to check for "rented less than 15 days."  And how would IRS know that there are no additional days rented to others at less than $600 so no 1099 was issued?  

If IRS tells me that reporting the income and an offsetting expense on Schedule E is the wrong thing to do, I am loath to disobey just to trick the computer.  I would attach a one-paragraph statement to the return, explaining why the rent is not included in gross income.  Especially if the amount involved is less than $5,000 and the client is in a 10% bracket, because that's unlikely to generate a CP-2000.  But I understand that others play the game differently.