The statement of accounts was prepared in an informal, not accounting-based form by...

"pro forma" means an accounting presentation which is useful for understanding a point the writer is trying to make but is not in accordance with governing accounting principles.
For example, a real estate company may want to present its funds from operations without consideration of conversions of employee incentive options, because the granting of those options is fairly uniform from year to year but the exercise of them is irregular, tending to distort the picture of the trend of actual company results. Similarly, a pro forma statement may be provided which omits consideration of certain one-time acquisition costs because those costs are really good for 20 years or more.