Well if you want to be mean about it those are IBM PC Compatible supported keys, not "Windows" keyboard shortcuts.

Granted most applications do support it, but Microsoft no longer lists them on their KB for Windows Shortcut Keys.

Keyboard Shortcuts for Windows
http://support.microsoft.com/kb/126449

Windows Program Key Combinations
• CTRL+C: Copy
• CTRL+X: Cut
• CTRL+V: Paste
• CTRL+Z: Undo
• CTRL+B: Bold
• CTRL+U: Underline
• CTRL+I: Italic