What is a Proof of Publication (PoP) in Kaspa?

A Proof of Publication (PoP) in Kaspa is a cryptographic proof that a transaction was published in a specific block — which is a separate guarantee from proving the transaction was accepted. To generate a PoP, Kaspa locates the block C where the transaction was published, then finds the earliest selected chain block B that has C in its past; the proof consists of a PoChM for B, a chain of headers from B to C, and a Merkle proof that the transaction appears in C's ATMR. Publication and acceptance are distinct steps in Kaspa's blockDAG, so the PoP lets anyone verify when a transaction entered the DAG, even before it is finalized. Understanding this distinction helps you follow exactly where your transaction stands in Kaspa's confirmation process.