The first file, sub , contains subscriber information. Subscriber is a unique code assigned to each subscriber by the user. Address is two lines of the subscriber's street address. The other field contents should be obvious from the field name. The next file, mag , holds information about each magazine.
Title is the title of the magazine being sold.
Subscribers is the total number of subscriptions to this magazine. The last file, script , contains information about each subscription. Magazine is the code of a valid magazine in the magazine file. Issues is the number of issues left on this subscription. Started is the date the subscription was started.