Fictitious or fake entries are deliberately incorrect entries in reference works such as dictionaries, encyclopedias, maps, and directories, added by the editors as copyright traps to reveal subsequent plagiarism or copyright infringement. There are more specific terms for particular kinds of fictitious entry, such as Mountweazel, trap street, paper town, phantom settlement, and nihilartikel.
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients.
Mailing lists are often rented or sold. If rented, the renter agrees to use the mailing list only at contractually agreed-upon times. The mailing list owner typically enforces this by "salting" (known as "seeding" in direct mail) the mailing list with fake addresses and creating new salts for each time the list is rented. Unscrupulous renters may attempt to bypass salts by renting several lists and merging them to find common, valid addresses.