file under

file under (something)

To put something, often paperwork, in a file that has a particular name or designation. File these papers under "miscellaneous" for now—we'll get to them later.
See also: file

file under

v.
To store some document or information in a place with some name, label, or symbol associated with it: The contract was filed under her married name. The lawyer filed the documents under the appropriate heading.
See also: file
References in classic literature ?
Sometimes a group of squalid old crones, squatting in a file under the shadow of the steps to a porch, scolded noisily as the archdeacon and the bellringer passed, and tossed them this encouraging welcome, with a curse: "Hum
Thus, such foreign corporations may take advantage of both extensions--to file under Regs.