If you are reimbursed under an accountable plan, then reimbursements may be tax free. For example, if reimbursements for your mileage exceed the IRS standard mileage rate, then only amounts up to the rate are tax free; excess reimbursements are taxable.
Debt on which a person is not personally liable. In case of nonpayment, the creditor must foreclose on property securing the debt. At-risk rules generally bar losses where there is nonrecourse financing, but an exception applies to certain nonrecourse financing for real estate.