### Howto replace a stuck transaction with another with higher fee ?

bitcoind 0.15.0

The marking option "Request Replace-By-Fee" in the sending transaction GUI page should have a better understandable text.

The sender does not "request" anything when creating the transaction. This is just a tag for a later possibility, as I understand as a rather normal user.

I would suggest something like

"Let me increase the fee of this transaction later, if it should not get confirmed in expected time ('Replace-By-Fee' feature)"
{
    if (model && model->getAddressTableModel())
    {
        
        CoinControlDialog::coinControl->destChange = CNoDestination();
        ui->labelCoinControlChangeLabel->setStyleSheet("QLabel{color:red;}");
        const CTxDestination dest = DecodeDestination(text.toStdString());
        if (text.isEmpty()) 
        {
            ui->labelCoinControlChangeLabel->setText("");
        }
        else if (!IsValidDestination(dest)) 
        {
            ui->labelCoinControlChangeLabel->setText(tr("Warning: Invalid Bitcoin address"));
        }
        else 
        {
            if (!model->IsSpendable(dest)) {
                ui->labelCoinControlChangeLabel->setText(tr("Warning: Unknown change address"));
                
                QMessageBox::StandardButton btnRetVal = QMessageBox::question(this, tr("Confirm custom change address"), tr("The address you selected for change is not part of this wallet. Any or all funds in your wallet may be sent to this address. Are you sure?"),
                    QMessageBox::Yes | QMessageBox::Cancel, QMessageBox::Cancel);
                if(btnRetVal == QMessageBox::Yes)
                    CoinControlDialog::coinControl->destChange = dest;
                else
                {
                    ui->lineEditCoinControlChange->setText("");
                    ui->labelCoinControlChangeLabel->setStyleSheet("QLabel{color:black;}");
                    ui->labelCoinControlChangeLabel->setText("");
                }