Disc with the RW or RE specification can be erased, as long as your recorder supports this feature.
Two erase methods are available for this purpose:
Quick erasing does not remove the data physically from the disc, but instead only makes it inaccessible by erasing the references to existing content. The data can be restored.
Complete erasing removes the data from the disc by overwriting it with zeroes. The contents cannot be restored with conventional methods. Repeated full erasing increases the probability that third parties will not be able to reconstruct the contents.