Check any field that must not repeat — typically just the primary task or record ID. Unchecked fields (like annotator_id, label, review_status) are allowed to repeat freely.

Check any field that should not trigger a missing-field error when blank.

When should you use this? Some fields in your delivery only make sense for certain types of records — for example, a background_type field might only apply to image assets, not audio. Or a field like notes might be intentionally left blank when an annotator had nothing to add. If the tool is flagging those as critical errors but you know the blanks are expected and acceptable, check them here. You are telling the validator: "this field does not need to be filled in for every record — that is by design, not a mistake."

This does not affect uniqueness checks. It only stops the "missing field" error from firing.