It is possible to rename the aliases within the header at all time. By double-clicking the alias, the text editor (8) opens, where you can change the expressions.

Text Editor
To get a better overview, the header for the PARCEL data can be formatted, by defining a frame color (9).
On the preview tab (10) you get a clear overview of the so far embedded components in your template.

Overview of the embedded components

Preview of the embedded components