The file may include any number of data lines. While the format is flexible, and values may be of variable length, each value must be separated from the next by one or more spaces or a single comma. If one line is short of values, the next will be read to make up the set of 18, but a new case always begins on a new line. We cannot read .prn files, or any file that uses commas or dots to mark thousands. Spreadsheet files of any kind can not be read.
Some users are concerned about imputations.
Social security taxes on wages and business income are imputed for the states that have a deduction for that tax. Anything not listed above becomes a zero on the Form 1040. Zero is always a valid entry, although it may be inaccurate. Formerly we did an imputation for rent when property taxes were less than one percent of income. This has been dropped.