View source for Bitcoin Cash Memo as short public notes

Bitcoin Cash Memo is a name for short public notes carried on the Bitcoin Cash chain by the Memo protocol, including the notes that a front end such as memo.cash displays. A note is a small piece of data inside a transaction, not a post stored on a company server. This page explains what that difference amounts to, and what it does not solve: who the writer is, who can hide a note from readers, and whether a later reader can still find the point. It is a high-level description of the idea and the protocol. It does not give wallet steps, prices, exchange talk, or instructions for constructing a transaction.

== What Memo is ==

Memo is a protocol for on-chain social actions on Bitcoin Cash, together with front ends that display those actions. The protocol treats an address as the actor. Actions travel in a transaction output that carries data, using the chain feature commonly called OP_RETURN, rather than in a private database row. A short prefix marks the kind of action, so software can tell a post from a name setting, a reply, a follow, or a similar action. Post text is UTF-8. The published protocol caps a post at 217 bytes, so a memo is a sentence or a short paragraph, not an essay.

If the network accepts the transaction, the chain keeps that transaction in its history. A front end reads matching transactions and shows them as a feed. The feed is an interpretation. The note, in the strict sense, is the data in the transaction. Another client can read the same data and present it differently, or decline to present it.

People say a memo for one post and Memo for the protocol and its best-known site. This page uses Bitcoin Cash Memo for the whole arrangement: short notes, on this chain, under this protocol. The page does not claim that every short note ever placed on Bitcoin Cash follows the Memo prefixes. Other data conventions exist. A note counts as a Memo note when it follows the Memo action format.

== How a short note on a chain differs from a social post ==

A typical social post lives in a database a company controls. The company can edit the text, hide it, rank it, or remove the account. Readers see what that software chooses to show. A policy change, a legal demand aimed at the company, or an outage can remove the post from that view even when the writer objects. The post can be long, can sit above a comment thread under house rules, and can be ranked by logic the reader does not control.

A Memo note differs at the storage layer. The writer submits a transaction that includes the text. After acceptance, the text rides with that transaction. There is no edit in place. A correction is a later transaction. Taking a note off one website does not pull the bytes out of a chain history that already includes them. Readers who use only that website can still lose the view, because the website is a window, not the log.

Replies in the protocol are their own actions. A reply points at an earlier transaction and carries a short text of its own. That is still a chain note, not a hosted comment system with a single owner who can rewrite the thread. Nothing in the base protocol ranks a note onto a stranger's home screen. Any ranking lives in a client, and a different client can ignore it.

The difference is not that a chain note is wiser, kinder, or more true. The difference is that the bytes, the address on the action, and the place of the transaction in the chain are public facts. A later reader can check those facts against the transaction, if the reader can locate it. The meaning of the words remains the writer's text. The chain does not grade that meaning.

== Identity ==

The protocol binds a note to a key and an address, not to a civil name or a person a registry has checked. Whoever controls the key can write as that address. Whoever loses the key cannot write further actions as that address. A display name is more text chosen by the key holder, and another person can choose a similar name. The chain can show that two names differ by address. It cannot show which human sat at which key.

A note therefore does not solve impersonation, and it does not show who is speaking before the words are trusted. Any proof of a human identity has to come from another channel. This page does not offer that channel. It only refuses the idea that an address is a person.

== Moderation ==

Because the bytes stay in the chain, a moderator at one site cannot erase them for every future reader by deleting a row. That persistence is the property people point to when they say a note is hard to censor after it is accepted. It is also a limit. Harassment, private facts, and content that breaks a law do not become acceptable because a transaction stored them. Clients can refuse to display an address or a note. The protocol includes mute and unmute actions, which are themselves chain data about what a user prefers not to see. Those tools change a view or record a preference. They do not install an editor who can make the shared history forget.

Communities that need takedown, context warnings, or legal process still need those tools at the layers they actually control: indexes, websites, workplaces, and courts. Aiming the wish for deletion at the chain log misunderstands which layer can comply. This page does not describe how to build filters or how to post. It marks the split. Persistence of bytes and responsibility for display are different jobs, and Memo assigns them to different places.

== Whether later readers can find the point ==

Durability is not discovery. A later reader who already has the transaction identifier can ask a node or an archive for that transaction and read the data, for as long as some holder of the chain history will serve it. A later reader who remembers only a topic, a phrase, or a display name must use an index: a front end, a search service, or a copy someone kept on purpose. If those indexes close, the note can remain in the history and still be impractical to find. The protocol does not file notes under a library subject with a guarantee that future software will query it. Topic actions exist in the protocol, and a topic is only another short string inside an action, not a catalog that maintains itself.

Shortness makes the problem sharper. A note of at most 217 bytes carries little context. Later, the thread that made the sentence intelligible may be scattered across clients that no longer run, even when each reply transaction still sits in the history. A reader who finds the sentence alone can miss the point. Keeping the bytes is not the same as keeping the thread in view.

Other public stores, including content-addressed files and wikis with exports, answer the long-document job. They are neighbors. A memo does not replace them, and they do not replace a short chain note tied to an address. A writer who wants a later reader to see the point still needs a pointer and a longer home for the essay. This page does not turn that advice into wallet steps.

== What a reader can and cannot check ==

A careful reader can check a few things without trusting one website. The transaction either contains the text or it does not. The address either matches the one the reader meant to follow or it does not. A reply either points at the earlier transaction or it does not. A front end that shows text the chain does not contain is showing a different object. A front end that hides a note is not proof that nobody wrote it.

From the chain alone, a reader cannot check that the text is true, that the address is a specific human, or that replies will stay easy to find. The chain is a log of accepted actions. It is not a court, a civil registry, or a library catalog.

== Conclusion ==

Bitcoin Cash Memo is a protocol, and a family of front ends, for short notes stored in Bitcoin Cash transactions. A note differs from a social post because the text sits in a chain log, a correction is a new transaction, and any one website is only a window. The arrangement does not solve identity, does not solve moderation for every reader, and does not promise that a later reader will find the point without an index and some surrounding context. Used with those limits in view, it is a way to leave a short public sentence that others can check against a transaction. Used without those limits, it is easy to mistake for a full social network, a registry of persons, or an archive that files itself.

== See also ==

* [[Post-Scarcity Tooling: When Compute and Storage Stop Being Scarce|post-scarcity tooling]]
* [[Content-Addressed Wikis: Permanence Without a Single Host|content-addressed wikis]]
* [[Permaweb Basics: How Arweave Makes Content Permanent|permaweb basics]]
* [[IPFS and Arweave for Agent Memory and Knowledge Bases|IPFS and Arweave memory]]
* [[Building a Second Brain on the Permaweb Without Losing Ownership|permaweb second brain]]

[[Category:Bitcoin Cash]]
[[Category:On-chain protocols]]
[[Category:Public notes]]
[[Category:Publishing]]
[[Category:Digital records]]