Decoding the hexadecimal nulldata output from appendrawmetadata

Question

Guys

Can you confirm the format of the hexadecimal string that is generated by appendrawmetadata as I want to convert this back to ascii and noticed there is an additional couple of characters that have been added to the string I originally added to the raw transaction....

 

Cheers

 

Marty

Answer 1

MultiChain's transactions used bitcoin's formatting, so this is probably the OP_RETURN opcode (0x6A) and a length byte. The general transaction format is described here:

https://en.bitcoin.it/wiki/Transaction#general_format_of_a_Bitcoin_transaction_.28inside_a_block.29