[ercoupe-tech] Placard

[heavensd]

There is a data placard for an Ercoupe being sold, by itself, at E Bay.
(Item number: 190192151366) This may be a naive question, but I can't
imagine what a person could do with a placard by itself, other than
keeping it as a collectible... Anybody care to enlighten my innocent.
naive mind?
Eliacim