I've never seen that term used in cases where loans between related parties were under dispute.I would be more interested in demonstrating the interest was reasonable based market research, there is evidence of repayment, evidence of any collateral, consistent treatment as a loan on both tax forms, inclusion of interest income for him and interest deductions for you, there were provisions for enforcement of collection on nonpayment, amortization schedule, etc.Remember, it is canon that substance takes precedence to form.

Your windows need treatments.

I see a lot of questions about personal residence disposals and their tax treatment so I figured I would just post a quick summary.I once read that there is no other asset class given greater preference by tax law than real estate.Here is an example under 121.If you sell a personal residence and meet the ownership and use tests, you can exclude up to 250,000, or 500,000 if married filing jointly.

Literally rehabbing a rental with binds, the costs for window treatment has more then doubled.  

(And another common misconception that passive investing doesn't allow the investor to participate in some or all of the depreciation, or QBI etc.).But, in general, any tax treatment you are getting by purchasing directly can be duplicated through a limited partnership/LLC for passive investors.For example, here is a website that is devoted completely to passive investments that both allow someone to 1031 exchange into and out of them: 1031 crowdfunding.com.

We had roaches recur for a couple months after treatment was completed the first time.

You want a company with A-ratings across the board, that is a mutual company with non-direct recognition.Once your policy is created and funded and time has passed to allow for the growth of sufficient cash values (and this will change from policy to policy), you can begin borrowing from it as a source of private capital.Unlike the other financing sources mentioned above, using your policy offers an immediate source of funds without any obstacles.The benefits of cash flowing life insurance are as follows:-quick and simple loan approval-Does not impact your credit score-Does not add risk by hindering real property-Low fees and low interest rates-Growth continue in policy regardless of loans – known as non-direct recognition-Peace of mind in controlling your own loans instead of relying on a bankIn addition, the Cash Value Life Insurance Policy provides:-Guaranteed cash value accumulation-Guaranteed leveraged death benefits-Secured fixed premiums payments-Dividends-Tax preferred treatment-Creditor protection, as well as possible litigation and bankruptcy protection-Privacy, use, and controlWhen you borrow from a policy, you’re borrowing from your own cash value life insurance policy, so your approval and financing can be issued in literally hours.

Tax Advantages: Mobile Home Parks often offer tax advantages through depreciation deductions, 1031 exchanges, favorable capital gains treatment, and deductible expenses to name a few.Scalability: Mobile home park investments typically offer opportunities to scale your portfolio, diversify holdings, and spread risk across multiple properties in multiple markets since they can be easier to manage remotely if you have enough scale for a team.

I wasn't aware of the difference @Jason Wray alluded to as to how ownership type affects tax treatment of closing costs.   

Unless you elect special tax treatment they have absolutely zero effect on taxes.