Checking the "Keep" box for a field causes your selection to persist after the form is submitted and can be helpful for choice fields, like "Unit", or for batch entries where the same value is selected multiple submissions in a row. By default, all fields are cleared on a successful submission.
Example: performing multiple observations on a single unit. After selecting the unit, you can select the Keep button for that field. After the submission that field will retain the selected unit but the other fields will be cleared like normal.
Keep All
For convenience, there is also a "Keep all" button near the top of the form. This toggles the Keep option on and off for all fields in the Audit Form. This can be a time saver if most or all of the fields need to be marked with Keep.