Can not be used by unauthorised users.

The first item is explained under the heading Copy Protection, while the second and third one are explained under the heading View-Security Protection. Even though the both headings are accomplished in the same frame they are here split for the sake of better understanding.

Copy protection prevents unauthorised access of the programs, applying certain protection techniques. It is ineffective and impractical to protect the programs against DOS or Windows copy utilities. A better idea, which can be used instead, is to make the programs depended on objects, which can not be duplicated. This object can be a hardware device, a diskette or a Hard Disk. However, the object must be unique and unduplicatable. If you copy the program and try to run it on another machine, it will not run without the object on which the program is dependent.

Security programs are operating on the files with extension COM or EXE and prevents the files from being viewed or modified. Since the protected program is changed by the Security programs, the program with the View-Security strongly resists to the programs used for viewing the program code (debuggers). View-Security protection, however, does not prevent the file from being copied and can be used with the other protection programs.