BIP141: New commitment structure, sigop limits, etc #277

  91 |  
  92 | -The first levels bits of locator, interpreted in little endian, are assumed to be the position in the leaves of the Merkle tree where the witness root hash goes.
  93 | +=== Witness program ===
  94 |  
  95 | -The coinbase's input's witness must consist of a single byte array, which the size must be a multiple of 32 bytes but not bigger than 32*32 bytes. These are assumed to be the Merkle path to connect the witness root hash to the commitment root hash. Depth of the commitment is determined by the length of the path. If the depth of the tree is 0, the path should be represented by 0x00, and the witness root hash will be same as the commitment root hash.
  96 | +A scriptPubKey (or redeemScript as defined in BIP16/P2SH) that consists of a 1-byte push opcode (for 0 to 16) followed by a data push between 2 and 32 bytes gets a new special meaning. The value of the first push is called the "version byte". The following byte vector pushed is called the "witness program".

afk11 commented at 11:49 PM on January 11, 2016:

Anything beyond 17 is two bytes, should it be called version byte?

jl2012 commented at 3:34 AM on January 12, 2016:

Only 0-16 are defined. Anything beyond 17 has no special meaning.