Put a fixed banner cell at the top of a notebook.

In the Current Notebook...

Add a banner to the top of the current notebook by setting the DockedCells option:

In a New Notebook...

Create a notebook with a banner:

Set the DockedCells option to add a banner to the current notebook:

Set the DockedCells option to add a banner to the current notebook. Scroll past the top of the notebook (iOS) or press the Refresh button (Android) to refresh, making the banner visible:

Notes

The value of DockedCells requires low-level representations of typeset cells, typically constructed using Cell, BoxData, TextData and ToBoxes: