# Glossary

Every Atomicals and ARC-20 term used on this site, defined once and used consistently everywhere.

Page ID: start/glossary
Applicability: protocol-behavior
Authority: reference-implementation
Networks: mainnet
Verified: 2026-08-31
Locale: en
URL: https://bitcoinuniverseio.github.io/atomicals-and-arc-20/start/glossary/

---
Terms in this glossary are the ones used across the site and in every translation. Code
identifiers, schema property names, operation names, and hashes are never translated.

## Core

**Atomical**
: A digital object created by a Bitcoin transaction and carried by a Bitcoin output.

**Atomical ID**
: The durable identity of an Atomical, written `<txid>i<output-index>`. Assigned once, never changes.

**Atomical number**
: A sequential number assigned in mint order. Useful for display. Not the identity to store.

**Location**
: The unspent output that currently carries an Atomical. Changes on every move.

**Envelope**
: The witness script structure carrying `atom`, an operation, and a CBOR payload in the reveal transaction.

**Operation**
: The short code inside the envelope that tells a validator what to do. Examples: `ft`, `dft`, `dmt`, `nft`, `mod`, `sl`.

**Commit and reveal**
: The two-transaction pattern. The commit pays to a Taproot output; the reveal spends it and exposes the envelope.

**Bitwork**
: A proof-of-work style prefix requirement on a transaction id, used to gate mints and claims.

**Candidate**
: A pending claim for a globally allocated name or ticker, before rules resolve a winner.

**Verified winner**
: The Atomical that the rules resolved as holding a name or ticker.

**Generation**
: An immutable snapshot of an index at one consistent chain position.

**Reorg**
: A Bitcoin chain reorganisation that can invalidate previously indexed results.

## ARC-20

**ARC-20**
: The Atomicals fungible token model. One unit is one coloured satoshi.

**Ticker**
: A globally allocated ARC-20 name. Not proof of creator identity.

**Coloured UTXO**
: A Bitcoin output that a validator recognises as carrying ARC-20 value.

**Cardinal UTXO**
: An ordinary Bitcoin output with no Atomicals value. Used for fees and change.

**Direct FT**
: A one-step `ft` mint that places the whole supply in output zero.

**DFT**
: A decentralised fungible token deployment created with `dft`.

**DMT claim**
: A single mint against a DFT deployment, using the `dmt` operation.

**Perpetual DFT**
: An activation-gated decentralised mode with progressing Bitwork and an optional global cap.

**Mint amount**
: The exact satoshi value each valid DMT claim places in output zero.

**Max mints**
: The number of valid fixed-mode claims a deployment allows.

**Allocation**
: The validator's decision about which output receives how much coloured value.

**Normal allocation**
: The default coloring behavior when no operation payload changes it.

**Burn**
: Coloured value that could not be placed in any eligible output and is therefore destroyed.

**Split**
: The `y` operation, which separates fungible value at one output.

**Custom coloring**
: The `z` operation, activation gated, which assigns coloured value explicitly.

**Splat**
: The `x` operation on the non-fungible branch, separating multiple Atomicals held at one output.

**No-inflation validation**
: The rule that coloured output totals cannot exceed coloured input totals.

## Names and collections

**Container**
: A named collection identity that items can prove membership in.

**DMINT**
: Decentralised minting of Container items against a sealed manifest.

**Sealing**
: Making an Atomical or a Container manifest permanently unchangeable.

**Realm**
: A top-level Atomicals name owned as an NFT.

**Subrealm**
: A child name claimed under a parent Realm's rules.

**Payname**
: A Realm used as a payment destination.

**IDNA**
: The internationalised domain name rules used when comparing and normalising names.

**Confusable**
: Two distinct names that render similarly enough to deceive a reader.

## Integration

**Cursor**
: An opaque, signed pagination token that refers to a stable position in a generation.

**Readiness**
: Whether a service can currently answer correctly, distinct from whether it is configured or running.

**Freshness**
: How far behind the chain tip an index currently is.

**Idempotency key**
: A client-supplied key that makes a repeated mutation safe to retry.

**Request ID**
: A per-request identifier returned in responses and logs, used to trace one call.

**PSBT**
: A partially signed Bitcoin transaction, the exchange format between a service and a wallet.

**BIP-322**
: A message signing scheme used here to prove control of an address without moving funds.

**SIGHASH**
: The flag that decides which parts of a transaction a signature commits to.

## Terms we avoid

These words appear in third-party material and are not used as claims on this site: guaranteed,
risk-free, backed, collateralised, price floor, redemption. Where a source uses them, the page
quotes the source and says what evidence exists.