To return to a previous field on a form you are verifying, select ð Previous field. This is convenient when you are fast-verifying multiple lines and columns (see Layout). The keyboard shortcut is Ctrl+BkSp.
Changes made to the current field are discarded.
You can go back up to 50 fields.
In normal mode you can back up only to fields on the same form. To return to a field on a previous form, select ð . Then double-click any field to examine or change the value recorded for it.