Digital materials are listed as Vulnerable when the technical challenges to preservation are modest but responsibility for care is poorly understood, or where the responsible agencies are not meeting preservation needs. This classification includes Lower Risk materials in the presence of aggravating conditions.

Digital materials are listed Endangered when they face material technical challenges to preservation or responsibility for care is poorly understood, or where the responsible agencies are poorly equipped to meet preservation needs. This classification includes Vulnerable materials in the presence of aggravating conditions.

Digital materials are listed Critically Endangered when they face material technical challenges to preservation, there are no agencies responsible for them or those agencies are unwilling or unable to meet preservation needs. This classification includes Endangered materials in the presence of aggravating conditions.

Digital materials are listed as Practically Extinct when the few known examples are inaccessible by most practical means and methods.  This classification includes Critically Endangered materials in the presence of aggravating conditions.