diff --git a/bip-0321.mediawiki b/bip-0321.mediawiki
index ea8810e2e8..a917f617ec 100644
--- a/bip-0321.mediawiki
+++ b/bip-0321.mediawiki
@@ -24,7 +24,7 @@ This BIP proposes a URI scheme for describing Bitcoin payment instructions.
 
 The purpose of this URI scheme is to enable users to easily make payments by simply clicking links on webpages or scanning QR Codes.
 
-This BIP is a modification of [[bip-0021.mediawiki|BIP 0021]] to add information about the modern usage of bitcoin: URIs (including standard query parameters and modern address types) as well as provide forward-looking guidance on how to incorporate new payment instructions. It further adds an optional extension to provide the payment initiator with proof of payment. BIP 21 was based on BIP 20, which was, in turn based on an earlier document by Nils Schneider.
+This BIP is a modification and intended replacement of [[bip-0021.mediawiki|BIP 0021]] to add information about the modern usage of bitcoin: URIs (including standard query parameters and modern address types) as well as provide forward-looking guidance on how to incorporate new payment instructions. It further adds an optional extension to provide the payment initiator with proof of payment. BIP 21 was based on BIP 20, which was, in turn based on an earlier document by Nils Schneider.
 
 == Specification ==
 
@@ -120,6 +120,12 @@ For payments completed on-chain, this is largely addressed by having the payment
 
 In order to avoid inadvertently revealing the sender's IP address or other information to the recipient, proof URIs must only be opened when they will simply switch to another locally-installed application (i.e. the application which initiated the payment). When clicking a URI from a website, the website should already have plenty of logic on its backend to process payment completion and a proof-of-payment callback is unnecessary.
 
+== Reference Implementation ==
+
+Documentation: https://docs.rs/bitcoin-payment-instructions
+
+Code repository: https://github.com/rust-bitcoin/bitcoin-payment-instructions
+
 == Forward compatibility ==
 
 Query parameter keys which are prefixed with a req- are considered required.  If a client does not implement handling a query parameter which has a key prefixed with req-, it MUST consider the entire URI invalid.  Any other query parameters which are not implemented, but which are not prefixed with a req-, can be safely ignored.