# Inscriptions

Files bound to sats by ord: the witness envelope that carries them, the commit and reveal, recursion and delegation, cursed inscriptions, and how BTI books their bytes.

URL: https://blockspace.wiki/concepts/inscriptions/

An [inscription](https://blockspace.wiki/glossary/inscription/) is a file bound to a sat. Blockspace Value Theory's protocol roster dates ordinals inscriptions to January 2023 and describes them as arbitrary files bound to individual sats, carried in a Taproot witness envelope. This page covers how the bytes are carried, how [BTI](https://blockspace.wiki/glossary/bti/) books them, and the variants BTI's documents cover: recursion, delegation and cursed inscriptions.

## Content, not a token

Under BTI's law an inscription is content, and the sat it is bound to is the token (ruleset B14). The chain runs label → content → token, and only the token claims. So an inscription's bytes appear in the books of its sat: its file is the sat's [Book C](https://blockspace.wiki/glossary/book-c/), and the transaction that revealed it is the sat's [Book B](https://blockspace.wiki/glossary/book-b/) and [Book A](https://blockspace.wiki/glossary/book-a/). See [sats and ordinals](/concepts/sats-and-ordinals/).

ord reported 128,170,184 inscriptions (as of block 972,320, 2026-10-20 12:17:53 UTC).

## The envelope

The data-types reference describes how the file is carried. An inscription sits in an [envelope](https://blockspace.wiki/glossary/envelope/) inside a taproot script-path spend: the leaf script holds `OP_FALSE OP_IF … OP_ENDIF` with the content in between, and the ord envelope's marker is `6f7264`. Three consensus facts shape it:

- each data push is capped at 520 bytes, which is why envelopes chunk their content into pushes of at most 520 bytes;
- tapscript leaf scripts have no script-size limit, so one leaf can hold megabytes of pushes, bounded only by transaction and block weight;
- witness bytes weigh 1 WU each, a quarter of base bytes. See [the witness discount](/concepts/witness-discount/).

The reference adds that standard relay's 80-byte stack-item caps do not touch inscriptions, because the data lives in the leaf script, not in stack items. It also notes that a reveal transaction has base bytes of its own, and that "the commit tx is a second, unmarked cost".

## Commit and reveal

A tapscript can only be revealed by spending an output whose taproot tweak commits to it. So an inscription takes two transactions: a commit and a reveal. BTI records the commit as an [enabler](https://blockspace.wiki/glossary/enabler/) of the reveal; the commit claims nothing itself, but its bytes join the reveal's pool and surface in Book A only.

Case 7 of the BTI case studies (2026-08-10) is a 3,888,767-byte jpeg, inscription #127,057,930, revealed at block 960,962:

| | bytes |
|---|---|
| the file (Book C) | 3,888,767 |
| the whole reveal (Book B) | 3,911,459 |
| reveal plus its 419-byte commit, mined 56,161 blocks earlier (Book A) | 3,911,878 |

Of the reveal's structure, 22,457 bytes are envelope framing, about 7,500 push prefixes at 520-byte chunks. ord's content length for the inscription equals the envelope's body exactly, so BTI's extractor and the definitional source agree on the file.

## Inscriptions that carry tokens

Some protocols write their operations as inscriptions. A BRC-20 mint is an inscription whose body is a small JSON text. Case 10, the first BRC-20 mint, has two claimants on one reveal: the sat (op `inscribe`) and the tick `ordi` (op `mint`). The tick shares only the envelope it was written in; the 71-byte JSON body is the sat's content, so the tick's Book C is 0. BRC-100 works the same way: its token table entry says the tick's Book C is 0 because the JSON body is the sat's content.

## Recursion

BVT's roster lists recursive inscriptions, from 2023, as carried in the witness "by reference", and notes that they reduce per-item consumption. BVT's §3.6 adds that recursive inscriptions and better encoding lower per-item consumption while raising "the prestige of efficiency". Blockspace Labs' research project on permanent bytes includes a part called "Reuse, not repeat": how many bytes recursion (`/content/`, `/r/`) and delegation save.

## Delegation

A [delegate inscription](https://blockspace.wiki/glossary/delegate-inscription/) displays another inscription's content. The block.space rankings documentation says such an inscription "bought a few hundred bytes and is that size": the largest-inscriptions board ranks bytes bought, not bytes shown. The holders appendix's inscription labels table carries a `delegate` column for this.

## Cursed inscriptions

ord counts [cursed inscriptions](https://blockspace.wiki/glossary/cursed-inscription/) apart from blessed ones. Its latest reading: 472,043 cursed and 127,698,141 blessed (as of block 972,320, 2026-10-20 12:17:53 UTC). A cursed inscription has a negative number; a BTI finding of 2026-10-19 cites #−10,508, at block 791,263.

That finding is open. Of the 100,000 largest inscriptions by body size, 582 had no sat binding in BTI's table, the first of them cursed, far below the ord export's ceiling. The finding gives two possible causes: an export that omits cursed inscriptions, or a mismatch in how the envelope's index is derived. Neither is confirmed as of 2026-10-19. Until it is answered, block.space shows those rows as "not yet attributed", with bytes, block and fee, never 0 and never dropped.

blockspacelabs.com lists cursed inscriptions as a research study: which rules cursed each inscription, by height, and how the books bind them to sats. Blockspace Holdings' documents do not list the rules themselves.

## The largest

The block.space board of largest inscriptions ranks by Book C, the file's own bytes with all framing removed: "the largest file ever committed to a Bitcoin block". The Ordinal Sats family holds 33.44 GB in Book C (as of block 972,299, 2026-10-20 09:30:48 UTC).

Sources:

- block.space docs: data types · https://block.space/docs/datatypes
- Blockspace Holdings records
- block.space docs: rankings · https://block.space/docs/rankings
- Blockspace Value Theory · https://block.space/docs/bvt
- The blockspacelabs.com page (index.html) · https://blockspacelabs.com
- ord /status (the blockspace.to ord server) · https://blockspace.to/status
- block.space protocols API · https://block.space/api/protocols

Live figures: ord as of block 972,320, 2026-10-20 12:17:53 UTC; protocols as of block 972,299, 2026-10-20 09:30:48 UTC

Updated: 2026-10-20