Why can't add an application keyboard shortcut as Shift+Letter?

[cliffzhu]

Hi,

System Preferences -> Keyboard -> Shortcut -> App Shortcuts

I am trying to add a keyboard shortcut here, I found I can add shortcut like
Command + C
Control + C
Option+C

But it does not allow me to add shortcut like
Shift + C

Why shift key alone can not be used as a keyboard modifier key? What is reason behind it?

 

[leman]

I can only guess here, but I would say that shift key is primarily used for inverting the case on the letters, so allowing it as a keyboard modifier would potentially mess up text fields. But I find it surprising that you can use the option key (for which the same reasoning applies).

At any rate, OS X has an internal logic to its modifier key usage and it is in general a good idea to stick to that for consistency (even though OS X is not fully consistent with it itself)

CMD key — shortcut for menu items
CTRL key — additional commands
OPT key — modify/extend behaviour of a key or a shortcut