When a specified attribute is currently set to its default value, the corresponding flag in the returned defaults mask is set and the returned value for this attribute is undefined.

The graphics engine either:

• Returns the value of each specified attribute and resets the corresponding bit in the returned mask, or

• Sets the bit in the returned mask to indicate that the specified attribute is set to its default. Note that the corresponding value in the attribute buffer is not valid and is likely to have been overwritten by the engine.