diff --git a/irc/help.go b/irc/help.go
index 67f74584..9208fbf2 100644
--- a/irc/help.go
+++ b/irc/help.go
@@ -64,6 +64,7 @@ Oragono supports the following user modes:
   +a  |  User is marked as being away. This mode is set with the /AWAY command.
   +i  |  User is marked as invisible (their channels are hidden from whois replies).
   +o  |  User is an IRC operator.
+  +R  |  User only accepts messages from other registered users. 
   +s  |  Server Notice Masks (see help with /HELPOP snomasks).
   +Z  |  User is connected via TLS.`
 	snomaskHelpText = `== Server Notice Masks ==
diff --git a/irc/modes.go b/irc/modes.go
index 80cbdaeb..f7a23772 100644
--- a/irc/modes.go
+++ b/irc/modes.go
@@ -101,6 +101,7 @@ const (
 	LocalOperator   Mode = 'O'
 	Operator        Mode = 'o'
 	Restricted      Mode = 'r'
+	RegisteredOnly  Mode = 'R'
 	ServerNotice    Mode = 's'
 	TLS             Mode = 'Z'
 	UserRoleplaying Mode = 'E'
@@ -110,7 +111,7 @@ const (
 var (
 	// SupportedUserModes are the user modes that we actually support (modifying).
 	SupportedUserModes = Modes{
-		Away, Invisible, Operator, ServerNotice, UserRoleplaying,
+		Away, Invisible, Operator, RegisteredOnly, ServerNotice, UserRoleplaying,
 	}
 	// supportedUserModesString acts as a cache for when we introduce users
 	supportedUserModesString = SupportedUserModes.String()
@@ -127,9 +128,9 @@ const (
 	Moderated       Mode = 'm' // flag
 	NoOutside       Mode = 'n' // flag
 	OpOnlyTopic     Mode = 't' // flag
-	RegisteredOnly  Mode = 'r' // flag
-	Secret          Mode = 's' // flag
-	UserLimit       Mode = 'l' // flag arg
+	// RegisteredOnly mode is reused here from umode definition
+	Secret    Mode = 's' // flag
+	UserLimit Mode = 'l' // flag arg
 )
 
 var (
@@ -281,7 +282,7 @@ func (client *Client) applyUserModeChanges(force bool, changes ModeChanges) Mode
 
 	for _, change := range changes {
 		switch change.mode {
-		case Invisible, WallOps, UserRoleplaying, Operator, LocalOperator:
+		case Invisible, WallOps, UserRoleplaying, Operator, LocalOperator, RegisteredOnly:
 			switch change.op {
 			case Add:
 				if !force && (change.mode == Operator || change.mode == LocalOperator) {
diff --git a/irc/server.go b/irc/server.go
index 5be7a09e..484021c6 100644
--- a/irc/server.go
+++ b/irc/server.go
@@ -1133,7 +1133,11 @@ func privmsgHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool
 				clientOnlyTags = nil
 			}
 			msgid := server.generateMessageID()
-			user.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "PRIVMSG", user.nick, splitMsg)
+			// restrict messages appropriately when +R is set
+			// intentionally make the sending user think the message went through fine
+			if !user.flags[RegisteredOnly] || client.registered {
+				user.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "PRIVMSG", user.nick, splitMsg)
+			}
 			if client.capabilities[EchoMessage] {
 				client.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "PRIVMSG", user.nick, splitMsg)
 			}
@@ -1829,7 +1833,11 @@ func noticeHandler(server *Server, client *Client, msg ircmsg.IrcMessage) bool {
 				clientOnlyTags = nil
 			}
 			msgid := server.generateMessageID()
-			user.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "NOTICE", user.nick, splitMsg)
+			// restrict messages appropriately when +R is set
+			// intentionally make the sending user think the message went through fine
+			if !user.flags[RegisteredOnly] || client.registered {
+				user.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "NOTICE", user.nick, splitMsg)
+			}
 			if client.capabilities[EchoMessage] {
 				client.SendSplitMsgFromClient(msgid, client, clientOnlyTags, "NOTICE", user.nick, splitMsg)
 			}