Maybe they have some purpose, but it isn't immediately obvious. I tried Tree & List mode, they're never populated.

![image](https://user-images.githubusercontent.com/13134193/33488849-04a2c8a6-d6ed-11e7-85c3-5c05f1ec5346.png)

* Bitcoin-Qt 0.15.1 for Ubuntu 16.04 x64 (from http://ppa.launchpad.net/bitcoin/bitcoin/ubuntu xenial/main amd64)

Note: I just noticed I'm *not* seeing this on Ubuntu 17.10 x64 with 0.15.1 downloaded from bitcoincore.org. 

![image](https://user-images.githubusercontent.com/13134193/33491553-9584dc62-d6f5-11e7-9ba7-e074e0e36151.png)


COLUMN_CONFIRMATIONS,
        COLUMN_TXHASH,
        COLUMN_VOUT_INDEX,
    };
    friend class CCoinControlWidgetItem;
private Q_SLOTS:
    void showMenu(const QPoint &);
    void copyAmount();
    void copyLabel();
    void copyAddress();
    void copyTransactionHash();
    void lockCoin();
    void unlockCoin();
    void clipboardQuantity();
    void clipboardAmount();
    void clipboardFee();
    void clipboardAfterFee();
    void clipboardBytes();
    void clipboardLowOutput();
    void clipboardChange();
    void radioTreeMode(bool);
    void radioListMode(bool);
    void viewItemChanged(QTreeWidgetItem*, int);
    void headerSectionClicked(int);
    void buttonBoxClicked(QAbstractButton*);
    void buttonSelectAllClicked();
    void updateLabelLocked();
};
#endif