Headers and footers can be composed of text or fields. Fields are
placeholders for values which will be substituted when the worksheet is
printed such as the sheet name, the page number and the current date.

Currently, the combo box and preview pane on the "Headers and Footers"* tab
of the "Print Setup" dialog show substituted field values. Choosing
"Customize header" or "Customize footer" from the combo box brings up a
dialog with the option to manually type in text or fields. In this case
fields are meant to be entered in the form &[fieldname]. However, this is
never mentioned anywhere. This could be made easier with an explicit list
of available fields.

In addition to the inconsistency of allowing a user to make quick
selections of header/footer combinations using substituted field forms and
customized header/footer values using fields of the form &[fieldname], the
substituted values don't correspond to expected behaviour.

This is especially true of the &[sheet] field which previews as "Sheet 1"
irregardless of the current sheet's name.

I suggest that the combo box selection shows the field values where
appropriate and that the preview pane show actual values (ie. with the
correct sheet name).

The customize dialog should have some means to automatically enter fields
(and thereby show all possible fields). Additionally, it should have the
preview pane in it as well.

Ideally, commonly used header/footer combinations should be added to the
combo box for quick selection in other documents.

* Should the tab be called "Header and Footer" since only 1 header and
footer are allowed?