> For the complete documentation index, see [llms.txt](https://help.tokenpocket.pro/en/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.tokenpocket.pro/en/wallet-faq-en/btc-wallet/op_return.md).

# What is OP\_RETURN？

To be easier, we can regard OP\_RETURN as a memo function, which can permanently write data into the Bitcoin network; Currently OP\_RETURN supports up to 80 bytes of data; punctuation marks, numbers, letters occupy 1 byte, and Chinese characters occupy 3 byte。