Wiktionary
file-card
n. 1 (context uncountable English) Material with embedded wire teeth used for cleaning files; card-clothing 2 (context countable English) A tool for removing debris from between the teeth of a file#Etymology 3.
Usage examples of "file-card".
She rooted past untidy bundles of canceled checks, dead C, D, and 9-volt batteries (for some reason she had never been able to shitcan old batteries what you did with old batteries was throw them in a drawer, God knew why, it was just the Battery Graveyard instead of the one the elephants were supposed to have), bunches of rubber bands and wide red canning-rubbers, unanswered fan letters (she could no more throw out an unanswered fan letter than a dead battery), and recipes jotted on file-cards.