diff --git a/gencapdefs.py b/gencapdefs.py
index 00ba435e..e1cfbc7f 100644
--- a/gencapdefs.py
+++ b/gencapdefs.py
@@ -213,6 +213,12 @@ CAPDEFS = [
         url="https://github.com/ircv3/ircv3-specifications/pull/506",
         standard="IRCv3",
     ),
+   CapDef(
+        identifier="NoImplicitNames",
+        name="draft/no-implicit-names",
+        url="https://github.com/ircv3/ircv3-specifications/pull/527",
+        standard="proposed IRCv3",
+    ),
 ]
 
 def validate_defs():
diff --git a/irc/caps/defs.go b/irc/caps/defs.go
index aa48a649..18ff5759 100644
--- a/irc/caps/defs.go
+++ b/irc/caps/defs.go
@@ -7,7 +7,7 @@ package caps
 
 const (
 	// number of recognized capabilities:
-	numCapabs = 33
+	numCapabs = 34
 	// length of the uint32 array that represents the bitset:
 	bitsetLen = 2
 )
@@ -65,6 +65,10 @@ const (
 	// https://github.com/ircv3/ircv3-specifications/pull/398
 	Multiline Capability = iota
 
+	// NoImplicitNames is the proposed IRCv3 capability named "draft/no-implicit-names":
+	// https://github.com/ircv3/ircv3-specifications/pull/527
+	NoImplicitNames Capability = iota
+
 	// Persistence is the proposed IRCv3 capability named "draft/persistence":
 	// https://github.com/ircv3/ircv3-specifications/pull/503
 	Persistence Capability = iota
@@ -162,6 +166,7 @@ var (
 		"draft/languages",
 		"draft/message-redaction",
 		"draft/multiline",
+		"draft/no-implicit-names",
 		"draft/persistence",
 		"draft/pre-away",
 		"draft/read-marker",
diff --git a/irc/channel.go b/irc/channel.go
index 4dc5bccb..a39035e8 100644
--- a/irc/channel.go
+++ b/irc/channel.go
@@ -885,7 +885,9 @@ func (channel *Channel) Join(client *Client, key string, isSajoin bool, rb *Resp
 	if rb.session.client == client {
 		// don't send topic and names for a SAJOIN of a different client
 		channel.SendTopic(client, rb, false)
-		channel.Names(client, rb)
+		if !rb.session.capabilities.Has(caps.NoImplicitNames) {
+			channel.Names(client, rb)
+		}
 	} else {
 		// ensure that SAJOIN sends a MODE line to the originating client, if applicable
 		if givenMode != 0 {
@@ -976,7 +978,9 @@ func (channel *Channel) playJoinForSession(session *Session) {
 		sessionRb.Add(nil, client.server.name, "MARKREAD", chname, client.GetReadMarker(chcfname))
 	}
 	channel.SendTopic(client, sessionRb, false)
-	channel.Names(client, sessionRb)
+	if !session.capabilities.Has(caps.NoImplicitNames) {
+		channel.Names(client, sessionRb)
+	}
 	sessionRb.Send(false)
 }
 
diff --git a/irc/handlers.go b/irc/handlers.go
index f3db4fe3..9778b32e 100644
--- a/irc/handlers.go
+++ b/irc/handlers.go
@@ -3169,7 +3169,9 @@ func renameHandler(server *Server, client *Client, msg ircmsg.Message, rb *Respo
 					targetRb.Add(nil, targetPrefix, "JOIN", newName)
 				}
 				channel.SendTopic(mcl, targetRb, false)
-				channel.Names(mcl, targetRb)
+				if !targetRb.session.capabilities.Has(caps.NoImplicitNames) {
+					channel.Names(mcl, targetRb)
+				}
 			}
 			if mcl != client {
 				targetRb.Send(false)