Spreadsheets have supported a full set of keys for a long time - arrows, Tab, F2, Home and End, jump-to-edge, find and replace, bold and italic, save and export - and none of it was written down anywhere. Pressing ? in a spreadsheet now lists all of it.
The same panel is available in Documents, Idea workspaces, the recording editor, book contents and the presentation viewer, which each had working keys and no way to discover them. Document menus continue to show their shortcut beside each command, and now print the key exactly the way the panel does.