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[[caption-width-right:350:No, ''Chik'N Bash'' is not an ''VideoGame/AngryBirds'' ripoff.\\
Pink pigs. Chickens. See? ''Totally'' original.]]
->''"It isn't '''like''' VideoGame/SystemShock2. It '''is''' ''System Shock 2''"''
-->-- ''WebAnimation/ZeroPunctuation'' reviewing ''VideoGame/BioShock1''
When an attempt to FollowTheLeader seems to be almost ''exactly'' like the leader, but with cosmetic identifiers (the "serial numbers") changed. The blatant copying of characters and plot is on a level that would make even makers of TheMockbuster blush. (Although that [[SincerestFormOfFlattery needn't mean the quality is bad....]])
Sometimes this can be by the very creators of the source work, perhaps as a form of applying CaptainErsatz to an entire series (see AlternateCompanyEquivalent).
So named because some stolen goods (particularly firearms) would have their identifying serial numbers filed off to make them untraceable.
Creator/RobertAHeinlein used this exact term in his book ''Literature/GloryRoad'': "That's the way with writers; they'll steal anything, file off the serial numbers, and claim it for their own."
Fanfic writers will sometimes convert their fanfics into original properties as an AscendedFanfic. In the event that the original fanfic is still available, you can directly see which character was filed off into which character by comparing the original fanfic with the new work.
Compare MissionPackSequel (when a follow-up is almost just like the first game), BetterByADifferentName, SpiritualLicensee, SpiritualSuccessor, TheyCopiedItSoItSucks, RecycledScript, DivorcedInstallment.
Contrast DolledUpInstallment, InNameOnly (both are when a work seems to have the serial numbers of another work scribbled on), ShoddyKnockoffProduct (a ripoff that seeks to look like a work, but is a very poor copy) LawyerFriendlyCameo (when shown as part of a work of fiction), BlandNameProduct.
'''No examples, please.''' This only defines a fandom term.