Edition Marker

What it is

An Edition Marker is a compact bitfield that records which edition numbers of a Master Edition have been printed. Rather than store a flag per edition in separate accounts, Metaplex packs 248 edition flags into a single 31-byte ledger.

Why it exists

Printing limited editions needs a way to prevent double-printing edition #42. Storing a boolean per edition in its own account would be wasteful; a bitfield lets one small account track hundreds of editions, with new marker accounts created only as edition numbers climb past each 248-edition block.

Byte layout

Total: 32 bytes.

How edition numbers map to bits

Edition number N lives in marker block N / 248; within that marker, it’s bit N % 248, addressed as byte (N % 248) / 8 and bit (N % 248) % 8. The marker account itself is a PDA seeded with the edition number’s block, so editions 1–248 share one marker, 249–496 the next, and so on.

Where you see it

Behind every limited-edition NFT drop. When you print edition #5 of a master, the program sets bit 5 in the relevant Edition Marker so #5 can never be printed again.

Common gotchas

• One marker covers 248 editions, not all of them. Large editions span multiple marker accounts, each a separate PDA. Don’t expect a single marker to hold the whole run.
• It’s a bitfield, not a counter. The supply counter lives in the Master Edition; the marker only records which specific numbers are taken. The two are updated together when printing.
• Bit ordering matters. Edition N’s bit is at byte (N % 248) / 8, MSB-first within the byte in Metaplex’s scheme. Off-by-one here prints the wrong slot.
• EditionMarkerV2 exists for very large editions in newer Metaplex versions; the classic 32-byte EditionMarker (key 7) is what you’ll see on most collections.