If a reviewer finds something that needs correcting in a form you submitted, they can return it to you. Returned forms appear at the top of the Current tab on the Forms screen with a red bar, and the reviewer's comment — for example Please fix — is shown under the form name.
If you're online, the form is sent straight away and moves to the History tab. If you're offline, it stays under Returned Forms with a blue bar and Waiting for sync to server until you sync — see Submitting a form.
If you're unsure what the reviewer is asking for, contact them directly.
Returned forms are also the only way to change a form that has already been sent to the server. If you need to correct one, ask your administrator or reviewer to return it to you.