File 13 is a popular military slang expression, that became widely used in the movie industry as well, as a way to allude to the garbage can.
It is an archaic way of saying Splish Splash Your Opinion is Trash, used to dismiss ideas and projects as useless.
Although the exact origin of the codename “File 13” is not known, the expression “File” used as a verb synonymous to “Discard” has been around in the United States as a slang expression since 1934.
“File 13” was first cited in a dictionary as a military jocular slang expression in 1941.
“File 13” spread rapidly among military personnel in the second half of the 1900’s, spreading to various other sectors of business, like bureaucracy and finance.
It was first defined on Urban Dictionary on May 18th, 2006.
A YouTube video, referencing the slang expression was uploaded to the video sharing platform by HarperKids on October 22nd, 2012.