Christian, the housing allowance is excluded from income tax only (unless the documented expenses are less than that amount). The allowance is included in the SE calculation unless the minister is retired. IRS 1402(a)(8); Treas. Reg. 1.1402(a)-11(a); Flowers v. Commissioner, T.C. Memo. 1991-542.
As mentioned in my earlier response, "Actual expenses can be supplies, maintenance, telephone, cable, etc." That would be on line 4d. So 4a would be the allowance, say, $5000. Probably 4b is blank but you have to ask. 4d. would be as mentioned and could add up to a fair amount. 4e is pretty clear but know what all the utilities are. It's quite likely that 4f then could be $6000+. Sometimes the utilities alone could be as much as the allowance. And often the FRV of the home is much higher than either the HA or the expenses. As Lion said then see that the lowest amount is the HA making none of it taxable for INCOME purposes. If the amount is higher than the others, the excess must be included on line 1 with wages. Click on that link and you will see Non W-2 Wages, Salaries, Tips, etc. line 16 Clergy excess allowance. This has happened to my clergy clients just once.
It's hard for me to imagine an NOL without a Sch. C and I don't think any unreimburse employee expenses could ever by offset by the housing allowance which is just that - for housing. It may be that the prior preparer was trying to save the unreimbursed expense deduction when 2106 went away.