Samsung SH-M522C-CSWN - Manual (Page 17)

To ensure a long service life for your discs and drive, follow the pre-cautions below when storing and cleaning
your discs.
Storing and Cleaning Your Discs
Do not place a disc in direct sunlight.
Store a disc vertically in a well-ventilated and stable location.
Do not write or attach a label on a disc.
Do not drop a disc or place heavy objects on it.
Do not touch the surface of a disc; hold it by the edges.
To clean a disc, polish lightly from the inside of the disc to the outside with a soft cotton cloth.
Do not leave the disc compartment open when you are not using it.
Using the Drive