BEA SWIFT Adapter - Manual (Page 78)

The Section Properties panel in the Header panel shows the properties of the header
block, such as whether it is Repeating and Optional. The Properties panel shows the
properties of a field (shown when a field is selected). It shows whether the field is
Optional and it’s Length. For fields of User Header block and Trailer, additionally the
Tag of the field is shown. The fields cannot be added, altered or removed for Header
and Trailer.