file off the serial numbers
To alter identifiable details in a creative work in order to conceal its origin.
Meaning adapted from Wiktionary, available under CC BY-SA 4.0.
“The author filed off the serial numbers to hide the story's true origin.”
“She files off the serial numbers to make her old blog posts look new.”
“To avoid a copyright lawsuit, the writer filed off the serial numbers of the famous characters and renamed them.”
“If you want to sell your fan fiction as a novel, you must file off the serial numbers so readers do not recognize the original movie characters.”
“The screenwriter filed off the serial numbers from his rejected script and moved the setting from outer space to a historical pirate ship.”
“By filing off the serial numbers of the original source material, the developer successfully transformed a fan-fiction project into an entirely original commercial game.”
The phrase originates from the practice of physically removing a firearm's identification marks to obscure its history. By filing the serial numbers off the metal, a person made the origin and ownership of the weapon difficult for authorities to trace, a procedure generally undertaken to ensure the object's previous life remained a matter of private record.
- 01
circular file
The trash container; the wastebasket.
- 02
crunch numbers
To figure; to do the math.
- 03
dirt file
A compilation of negative gossip or facts about someone.
- 04
do numbers
To be popular, as measured by engagement or sales metrics.
- 05
file away
To cause oneself to remember (something); to avoid expressing a feeling, fact or idea until an appropriate time.
- 06
make up the numbers
To provide sufficient people to make an event worthwhile.
- 07
rank and file
The members of an organization, community, etc. who are not in leadership positions.
- 08
run someone's file
To search through someone's criminal record.
Last updated August 10, 2026