With any software, the more you use it, the more hacks and shortcuts you discover, and never a truer word has been said when ...
The first reason why you might see double square brackets in a structured reference is that the column headers they refer to contain a special character. In these cases, the extra pair of square ...
You can freeze a row in Excel through the "Freeze Panes" menu. This lets you scroll through a spreadsheet without that frozen data leaving the screen.