If the field type is "Formula", it contains the expression evaluation result. The result can be modifed, but it can be recalculated at any moment by the fiscal statement calculation. This result is dependent on the fiscal year on the line. CAUTION, if the result is a date, in case of manual modification, the format needs to be complied with depending on the length. If the length is 8 the format is DD-MM-YY, if it is 10 the format is DD-MM-YYYY.