Number handling

This section gives the ability, if necessary, to override the settings under your operating systems regional settings. The default is 'Use system separators', but clearing this checkbox allows you to select a different decimal and thousands separator.

Printing

Certain countries have different 'default' paper size, this setting allows Excel, without altering you layouts, etc, to automatically switch from for example, European standard A4 paper to US standard Letter size, etc.

Right-to-left

Excel now has the ability to be adapted (since XP), to languages across the world that read from left to right rathern than the western left to right. It effectively moves the cell A1 from the top left of a sheet to the top right. Settings here alter the 'default' as well as the currently active sheet.