KnownTreasure is a structured reference for Indian coins and banknotes. The catalogue and guides are open to everyone; the collection and portfolio tools are private.
Every entry is grounded in a specimen held in the collection or a named standard reference, and photographed from the actual object. Where a figure — a date, a signature, a prefix range, a rarity — isn't verified, it isn't published.
Accounts are currently limited to the owner. Public sign-up, letting collectors track their own holdings, is planned.