What a digital artifact is
Bitcoin has no field for “this coin is a collectible”. Everything people call a digital artifact is built on top of ordinary transaction structure, and understanding which part of the structure carries it explains almost every surprising behaviour you will meet.
The three shapes
Section titled “The three shapes”An inscription
Section titled “An inscription”Data written into the witness of a transaction, and then treated as attached to one specific satoshi. Ownership follows that satoshi as it moves from output to output.
Practically: the inscription lives on one unspent output. The output usually holds a tiny amount, often 546 satoshis, because the value is what is written on it, not what it holds.
A token balance
Section titled “A token balance”An amount recorded in a ledger that indexers compute by reading the chain. The chain itself has no token balance field. Different indexers reading the same blocks can, in principle, disagree, which is why protocol support depends on a specific indexer being part of the evidence chain.
Practically: the balance is associated with an address or an output, according to that protocol’s rules, and moving the wrong coin can move or destroy the balance.
A rare satoshi
Section titled “A rare satoshi”A satoshi whose position in the issuance order is interesting: the first of a block, the first of a halving epoch, and so on. Nothing marks it. Its rarity is computed from where it sits in the sequence.
Practically: rarity is a property of a satoshi inside an output. Spend the output carelessly and the rare satoshi ends up wherever the change went.
Why this makes them fragile
Section titled “Why this makes them fragile”An ordinary wallet sees coins and amounts. It has no reason to treat a 546 satoshi output as anything other than a small amount of money, and it will happily use it to fund a payment or roll it into a fee.
That is not a bug in that wallet. It is a wallet doing exactly its job, on a chain where the artifact is invisible without an extra layer of interpretation.
Universe Wallet adds that layer before coin selection, which is the whole point of Protected outputs.
Why “supported” is a stronger word here than elsewhere
Section titled “Why “supported” is a stronger word here than elsewhere”Displaying a token balance requires an indexer. Moving one requires the wallet, the indexer, the API, the network, and reconciliation afterwards to all agree. A wallet that shows you a balance it cannot correctly move is more dangerous than one that shows nothing.
That is why the product treats support as something to be evidenced rather than declared. See What this release authorizes.