To display all options contained within a lookup list, simply click the down arrow beside the lookup field or use the keyboard shortcut Alt+↓.
For more efficient data entry, you may automatically narrow focus in any lookup list to values beginning with the letters that you type. Simply start typing the value appropriate for the lookup field to display a lookup list containing only those values that begin with the letter(s) that you have typed.
If you are changing a lookup field value, you may hit the Esc key at any time to populate the field with the value that was saved previously.
Note: If the lookup field is part of a hierarchy, any unsaved field values lower in the hierarchy may be erased.