Write once read many
From The Glossary of Digital Photography
Better known by its abbreviation WORM. A technology used with optical media such as CDs and DVDs that can be written only once and not changed but can be read many times.

ONLINE GLOSSARY OF DIGITAL PHOTOGRAPY
Better known by its abbreviation WORM. A technology used with optical media such as CDs and DVDs that can be written only once and not changed but can be read many times.