Google's own instructions for reversing an e-commerce transaction seem to contradict themselves regarding the unit price.

In the instructions it states

The item field has a positive per-unit price and a negative quantity.

yet, the code sample has a negative per-unit price and negative quantity.

_gaq.push(['_addItem',
       '1234',           // order ID - necessary to associate item with transaction
       'DD44',           // SKU/code - required
       'T-Shirt',        // product name
       'Olive Medium',   // category or variation
       '-11.99',          // unit price - required
       '-1'               // quantity - required
    ]);

Which is correct?