Can I create my own custom fields?

Yes, it is possible to create your own custom fields.

Using Admin > Edit Pupils > Custom Fields, clicking on +Add.  A row will appear at the bottom, simply type a name for your new custom field in the row.

NOTE; make sure that the name is unique across all fields as duplicate names will cause errors in your system.

Data can be added to these fields manually in the Admin > Edit Pupils > Pupil page by typing in the relevant cell.

Alternatively, you can easily import custom field data in bulk by adding to your assessment grade spreadsheet or creating a new spreadsheet adding columns for Forename, Surname, Gender and UPN, followed by the custom field and any other information you require.

In the 3rd step of the import, Map Data, set the Column Type to Custom and you will see a second dropdown appear that will let you choose your custom field name.