Meaning of the Columns of the mod spread-sheets

It would be nice-to-have a short document describing in a simple manner the meaning of each column in the spread-sheet under the folder "mod", in the UBL distribution package.

One benefit of having this document is to attach it (most of the times to refer to it), in business-specidifc documents where the models based on the UBL sprea-sheets.

Currently the only source of information where to find the concepts related to these columns are the NDRs, But the aims of the NDRs is different and identifying where these concepts are and what they mean is not always easy.