Remove uneeded error message, add more details on the original/proposal PSBT requirements

1 files changed, 23 insertions, 15 deletions

diff --git a/bip-xxxx.mediawiki b/bip-xxxx.mediawiki
index 7334e30..58dcd97 100644
--- a/bip-xxxx.mediawiki
+++ b/bip-xxxx.mediawiki
@@ -98,6 +98,26 @@ To ensure compatibility with web-wallets and browser-based-tools, all responses
 
 The sender must ensure that the url refers to a scheme or protocol using authenticated encryption, for example TLS with certificate validation, or a .onion link to a hidden service whose public key identifier has already been communicated via a TLS connection. Senders SHOULD NOT accept a url representing an unencrypted or unauthenticated connection.
 
+The original PSBT MUST:
+* Have all the `witnessUTXO` or `nonWitnessUTXO` information filled in.
+* Be finalized.
+* Not including fields unneeded for the receiver such as global xpubs or keypath information.
+* Be broadcastable.
+
+The original PSBT MAY:
+* Have outputs unrelated to the payment for batching purpose.
+
+The payjoin proposal MUST:
+* Use all the inputs from the original PSBT.
+* Only finalize the inputs added by the receiver.
+* Have all the `witnessUTXO` or `nonWitnessUTXO` information filled in.
+* Keep all the outputs unrelated to the payment.
+
+The payjoin proposal MAY:
+* Add inputs.
+* Add outputs.
+* Modify payment's output.
+
 ===Receiver's well known errors===
 
 If for some reason the receiver is unable to create a payjoin proposal, it will reply with a HTTP code different than 200.
@@ -116,29 +136,17 @@ The well-known error codes are:
 !Error code
 !Meaning
 |-
-|leaking-data
-|Key path information or GlobalXPubs should not be included in the original PSBT.
-|-
-|psbt-not-finalized
-|The original PSBT must be finalized.
-|-
 |unavailable
 |The payjoin endpoint is not available for now.
 |-
 |not-enough-money
 |The receiver added some inputs but could not bump the fee of the payjoin proposal.
 |-
-|insane-psbt
-|Some consistency check on the PSBT failed.
-|-
 |version-unsupported
 |This version of payjoin is not supported.
 |-
-|need-utxo-information
-|The witness UTXO or non witness UTXO is missing
-|-
-|invalid-transaction
-|The original transaction is invalid for payjoin
+|original-psbt-rejected
+|The receiver rejected the original PSBT.
 |}
 
 The receiver is allowed to return implementation specific errors which may assist the sender to diagnose any issue.
@@ -147,7 +155,7 @@ However, it is important that error codes that are not well-known and that the m
 Such error codes or messages could be used maliciously to phish a non technical user.
 Instead those errors or messages can only appear in debug logs.
 
-It is advised to hard code the description of the error codes into the sender's software.
+It is advised to hard code the description of the wellknown error codes into the sender's software.
 
 ===Receiver's original PSBT checklist===