If the authors in an organization need to be guided on what context each element in a structured application holds, then this is a great feature. For template designers, this is a feature that should definitely be explored because they can place a basic structure along with helpful information for authors who start authoring an XML. An instance of which can be seen while creating new DITA XMLs.
The term banner text looks misleading but this feature is about having placeholder content inside elements that guides the author with some text.
For example, we did a File .. New .. XML .. Dita Topic. It showed “banner” text in grey color, on which we could just click and start typing (it informs authors to type in the correct context), while the placeholder content vanishes.
So it actually guides the author in two ways:
- Where exactly to start authoring content in a document.
- Setting the context right for what context to author in.
Moreover, we foresee common usage where the placeholder can contain some warning/essential prerequisites that the author should be aware of. The Help guide says that you can extend this to content other than DITA too! (via EDD).