I've read that an OP_RETURN opcode allows up to 80 arbitrary bytes to be used in an unspendable transaction. My question is, how is it possible that in this famous transaction (d29c9c0e8e4d2a9790922af73f0b8d51f0bd4bb19940d9cf910ead8fbe85bc9b) are being pushed 983 bytes?
In detail:
Push data having size of 893 bytes. OP_CODES:
6a 4d d7 03
OP_RETURN OP_PUSHDATA2 (03d7 = 983 following bytes)