The Reserved List Checker is a tool that was created using HTML, CSS, and Javascript, and utilizing the API of Scryfall.
It works by accessing Scryfall to see if a card from the game "Magic the Gathering" is on something called "The Reserved List." The Reserved List is a list of cards that the makers of the game, Wizards of the Coast, has promised never to print.
The tool was made for Magic players that find themselves wondering whether older cards from the game that hadn't seen a printing beyond their initial run were on The Reserved List, or just cards that Wizards hasn't gotten around to reprinting yet.
To use the Reserved List Checker, enter the name of a card that you are curious about, and the checker will tell you if it is on The Reserved List. If it can't find the card you're referencing, or if there are multiple cards with the same name, it will let you know.