Field Tips

This is similar in concept to the dynamic help display shown here, but works even if there isn't blank page space adjacent to the fields. When the cursor is in a field, the field tip is displayed as a call-out to the right of the field.

From: Vox

This implementation could be improved by moving the field tip closer to the field, creating a tighter visual association.

Overall, this is an approach that works best for fields that users are likely to have "in focus" before making their entry. This is less likely for controls such as radio buttons, check boxes, and drop-down menus.