Bug 69424 TVT3.0: Multiple Mnemonics in Tasks -> Filters
From the main Workbench view, click the Task menu (drop down arrow) and select Filters. There are duplicated mnemonics for (D). See the attached screenshot.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/internal/MnemonicAssigner.java
private Set assigned = new HashSet();
    
    public boolean isReserved(char toCheck) {
        return assigned.contains(new Character(Character.toLowerCase(toCheck)));
    }
    
    /**
     * Returns the index of the mnemonic in the given string. Returns 
     * inputString.length() if the string does not contain a mnemonic.
     * 
     * @param inputString
     * @return
     * @since 3.1
     */
    private static int getAmpersandIndex(String inputString) {
        for(int idx = 0; idx < inputString.length(); idx++) {
            char next = inputString.charAt(idx);
            
            if (next == '&') {
                return idx;
            }
        }
        
        return inputString.length();
    }