DIN Norm
DIN 66399 defines the different classes of protection, categories of data carriers and security levels for the destruction of media containing confidential data.
With the new technologies, confidential data can be stored on multiple types of media (paper, hard disks, tape, etc.) and their destruction can be classified according to different levels of security defined according to the difficulty in reconstitute the information after destruction of the support. The DIN standard classifies data carriers into 6 categories, each represented by a letter.

THE DIFFERENT MEDIA TYPES
DIFFERENT PROTECTION CLASSES
DIN 66399 provides 3 protection classes: normal, high, very high. They determine the level of sensitivity of the data by a classification (internal data, confidential or secret) and allow everyone to know what is the level of security needed for the destruction of its data.