One of the WEIRDEST features of Word is that it (silently) retains keycombos that refer to a menu structure that was replaced many versions ago... simply to avoid irritating customers with trained reflexes.

Ctrl-o? Selects the Home menu.

Followed by 'e'? Deselects the Home menu, and presents the "Select Case" subwindow... like it did when it was on the Format menu, which no longer exists.

Documentation for this? Um, well...