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)


int column = treeWidget()->sortColumn();
    if (column == CoinControlDialog::COLUMN_AMOUNT || column == CoinControlDialog::COLUMN_DATE || column == CoinControlDialog::COLUMN_CONFIRMATIONS)
        return data(column, Qt::UserRole).toLongLong() < other.data(column, Qt::UserRole).toLongLong();
    return QTreeWidgetItem::operator<(other);
}
CoinControlDialog::CoinControlDialog(const PlatformStyle *_platformStyle, QWidget *parent) :
    QDialog(parent),
    ui(new Ui::CoinControlDialog),
    model(0),
    platformStyle(_platformStyle)
{
    ui->setupUi(this);
    
    QAction *copyAddressAction = new QAction(tr("Copy address"), this);
    QAction *copyLabelAction = new QAction(tr("Copy label"), this);
    QAction *copyAmountAction = new QAction(tr("Copy amount"), this);
             copyTransactionHashAction = new QAction(tr("Copy transaction ID"), this);  
             lockAction = new QAction(tr("Lock unspent"), this);                        
             unlockAction = new QAction(tr("Unlock unspent"), this);                    
    
    contextMenu = new QMenu(this);
    contextMenu->addAction(copyAddressAction);
    contextMenu->addAction(copyLabelAction);
    contextMenu->addAction(copyAmountAction);
    contextMenu->addAction(copyTransactionHashAction);
    contextMenu->addSeparator();
    contextMenu->addAction(lockAction);
    contextMenu->addAction(unlockAction);