The 6 rules for Creating and Formatting Two-Dimensional Data Files are:
- All data should be labeled (should have unique field names).
- Each experimental subject should have a unique study ID.
- Should be in rectangular format (flat files).
- Rows should represent the appropriate unit of analysis and columns should represent the unique attributes of the rows.
- Data files should contain the same number of columns in each row.
- Data should be atomic within each column.
However, if you are using REDCap, all of this is taken care of for you. In REDCap you do not have to explicitly address these rules.