How do I create a menu shortcut which involves the delete key? In Addressbook I want to create a keyboard shortcut for the Menu entry Delete Group using the key combination option-command-delete.

So I went to System Preferences --> Keyboard --> Keyboard Shortcuts and added an app-specific shortcut entry for "Delete Group". But when I tried to assign the key combination option-command-delete, my input wouldn't get accepted. (Combinations with letter like option-command-D work, though.)

How can I enter a shortcut combination involving the delete key?
You can edit the property list that stores the shortcuts directly. For example open ~/Library/Preferences/com.apple.AddressBook.plist with TextMate or TextWrangler, and add:

&lt;key&gt;NSUserKeyEquivalents&lt;/key&gt;
&lt;dict&gt;
    &lt;key&gt;Delete Card&lt;/key&gt;
    &lt;string&gt;~@&amp;#x0008;&lt;/string&gt;
&lt;/dict&gt;


The shortcut strings are documented in http://www.hcs.harvard.edu/~jrus/Site/Cocoa%20Text%20System.html.