OP_Return Function

From Termination to Data Storage

OP_RETURN is a script opcode used to terminate the script and return the top value on the stack. This opcode is analogous to the return function in programming languages. The OP_RETURN opcode has seen its functionality modified several times in its history in Bitcoin and as a result, has been primarily used as a means of storing data on the ledger.

Decoding OP_Return

OP_RETURN terminates the script leaving the stack as-is and letting the result on top of the stack determine the success or failure of the script. Note that if the top stack is non-empty and non-zero (zero including a string of zeros, of zero bytes), then it is considered as successful. Otherwise, it is considered as fail.

One of the most common uses of OP_RETURN is to create False Return scripts that can be used to generate provably unspendable transaction outputs. The most common usage of these scripts is to hold arbitrary formatted data for use in Application Layer Protocols. False Return outputs can be used to hold data, information pertaining to ownership rights, software elements, art and more.