in Delphi TIPS :: Sometimes you need to disallow a user from using keyboard shortcuts for common clipboard operations such as copy (CTRL+C) or paste (CTRL+V) while an edit control has the input focus.
Read the full article to learn how to Intercept and Block the CTRL+V Keyboard Shortcut
Related:
What if i’m using Shift+Insert?
@Dalu:
In case of SHIFT+INSERT you can check:
((ssShift in Shift) AND (Key = VK_INSERT))