What is an «Adjustment Refund» for a credit memo?

dmitrii_fediuk (Dmitrii Fediuk) March 17, 2016, 2:49pm 2

See also:

What is an «Adjustment Fee» for a credit memo?
How to make a partial refund?
Bug: the setAdjustmentPositive() and setAdjustmentNegative() methods of the \Magento\Sales\Model\Order\Creditmemo class wrongly use the \Magento\Sales\Model\Order's getGrandTotal() method instead of the getBaseGrandTotal() when an adjusment is in percent, so it lead to a wrong calculation result
How are the methods setAdjustmentPositive(), getAdjustmentPositive(), setAdjustmentNegative(), getAdjustmentNegative() of the \Magento\Sales\Model\Order\Creditmemo class used?
How are the methods setBaseAdjustmentPositive(), getBaseAdjustmentPositive(), setBaseAdjustmentNegative(), getBaseAdjustmentNegative() of the \Magento\Sales\Model\Order\Creditmemo class used?
How are the methods setAdjustmentPositive(), getAdjustmentPositive(), etAdjustmentNegative(), getAdjustmentNegative() of the \Magento\Sales\Model\Order class used?
How are the methods setBaseAdjustmentPositive(), getBaseAdjustmentPositive(), setBaseAdjustmentNegative(), getBaseAdjustmentNegative() of the \Magento\Sales\Model\Order class used?