CD-i 450 Tutorial Disc

The Compact Disc Interactive System brings a new experience to television: interactive programming using digital video and superior
Interactive sound reproduction that audiences have come to expect from the
Compact Dise medium.
In storing and handling your CD-i programme, you should apply the same care
as with conventional Compact Discs. No further cleaning is necessary if the
Compact Disc is always held by the edges and is replaced in its case directly after
playing. Should your CD-i disc display artifacts or playback problems, please
remove it from the player and wipe it with a clean and lint-free, soft, dry cloth,
always in a straight line from centre to edge. No solvent or abrasive cleaner
should ever be used on the disc.

Source: TheGamesDB