> For the complete documentation index, see [llms.txt](https://hub.bsvblockchain.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hub.bsvblockchain.org/wiki/bitcoin-script-and-opcodes/script/false-return.md). # False Return False Return outputs are transaction outpoints which begin with the script "OP\_FALSE OP\_RETURN". This script always returns a false when evaluated making the output unspendable and locking any funds attached to that endpoint. When attempting to spend the False Return output, OP\_FALSE will push "false" to the stack, after which OP\_RETURN is executed. OP\_RETURN terminates the execution immediately. The result of the execution is then read from the top of the stack. In this case, "false" is read, therefore the script fails regardless of what else is on the stack. False Return outputs can be used to store arbitrary information such as records, tokens, files and more. False Return outputs are commonly used as vehicles to carry data for application layer protocols inside Bitcoin transactions. 1. OP\_RETURN Outputs Due to changes made by Satoshi in 2010 to prevent people exploiting a bug in the Bitcoin software, the OP\_RETURN opcode was changed to force scripts to terminate in failure. This led to the widespread use of so-called 'Op\_Return outputs' which start with an OP\_RETURN instruction and then store data for application layer protocols. Bitcoin Core rules stipulated that to use an OP\_RETURN instruction in an output, it had to be both, the only opcode in the output, and the first opcode in the output. The Quasar Update in early 2019 relaxed these requirements to allow OP\_FALSE OP\_RETURN in preparation for the Genesis update in February 2020, where the original OP\_RETURN functionality was restored. The use of the OP\_FALSE, replicated the provably unspendable property of OP\_RETURN that many use cases have come to rely on. Many second layer protocols were built using the OP\_RETURN framework prior to being migrated to False Return outputs. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://hub.bsvblockchain.org/wiki/bitcoin-script-and-opcodes/script/false-return.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.