footer
If all rows in a column share the same value, e.g. first name, its recommended to place the value in a header or a footer.
<table>
<fields>diploma_id</fields>
<footer>diploma_id</footer>
If you rename a field, use the renamed value for the footer
<table>
<fields>diploma_id as nr</fields>
<header>nr</header>
If the data is of primary nature, you can use a header instead. Make sure the data is really unique, because the column will be hidden.
The first letter will be capitalized.
Use lowercase when possible