There’s plenty that have. Just one example: https://en.wikipedia.org/wiki/Milita...

		lxgr 46 days ago \| parent \| context \| favorite \| on: LetsEncrypt – Expiration Notification Service Has ... There’s plenty that have. Just one example: https://en.wikipedia.org/wiki/Military_payment_certificate Similar schemes have been used in the past as a forcing function against tax evasion or simply to phase out less secure older bills.