This should help.

Personal Property Rentals

• Report income and expenses related to personal property rentals on Schedule C (Form 1040)PDF, if you're in the business of renting personal property.
• Report income on line 8l and expenses on line 24b of Schedule 1 (Form 1040), Additional Income and Adjustments to IncomePDF, if you're not in the business of renting personal property.

Can I reserve now for a few days next year?  I am looking to rent it for November 8, 2024 through November 15, 2024.  It would be perfect for deer season next year.  He doesn't mind if we use it to hang up a couple of deer in case we get lucky does he?  Oh, I should ask - how much is he going to charge?

With one RV and hunting customers and partiers, I don't feel the RV will last long enough to qualify as a business!! It may not even last for your November 8th hunting reservation. 

You're escaping into the woods with guns the week after the election?  You know something we don't?

Aren't there companies that organize deals like this, they take care of all the rental arrangements and collect a commission on each one?  Also, they make a profit on selling the RV to you in the first place.  If you're dealing with one of those, ask for a reference from a customer who has ever made money on the deal. Otherwise, if this is mostly a method to turn personal expenses into tax deductions, IRS might hire enough auditors to catch some of those engaging in it.  

"Can" he claim it on Schedule C?  It sounds like he WANTS it to be a business.

As Camp pointed out, there is a good chance it would be on Schedule 1 instead of Schedule C.

HOWEVER, RV's are dangerous territory.  Assuming the RV has a place to sleep, cooking facilities and a toilet, then using it for personal for 14 days (or at least 10% of the rented days, if greater), would make it a "residence" for your client.  That essentially would mean many deductions would no longer able to be used.  So your client would likely want to use it LESS than 14 days a year, unless he wants to forfeit many of the deductions for renting it.

As of course any many of the allowable deductions (for example, vehicle insurance) will need to be split between personal use and rental use (probably based on days actually rented; not days available for rent).