Reply client tag

client-tags/reply.md

@@ -0,0 +1,53 @@
+---
+title: `+reply` client tag
+layout: spec
+work-in-progress: true
+copyrights:
+  -
+    name: "James Wheare"
+    period: 2016
+    email: "james@irccloud.com"
+---
+
+## Notes for implementing work-in-progress version
+
+This is a work-in-progress specification.
+
+Software implementing this work-in-progress specification MUST NOT use the
+unprefixed `+reply` tag name. Instead, implementations SHOULD use the
+`+draft/reply` capability name to be interoperable with other software
+implementing a compatible work-in-progress version.
+
+The final version of the specification will use an unprefixed tag name.
+
+## Introduction
+
+This specification defines a client-only message tag to indicate replies to other messages
+
+## Architecture
+
+### Dependencies
+
+Clients wishing to use this tag MUST negotiate the [`draft/message-tags`](../core/message-tags-3.3.html) capability with the server. Additionally, this tag relies on messages being sent with the [`draft/msgid`](../extensions/message-ids.html) tag. Clients SHOULD negotiate the [`echo-message`](../extensions/echo-message-3.2.html) capability in order to receive message IDs for their own messages, and therefore understand any replies.
+
+### Format
+
+The reply tag is sent by a client with the client-only prefix `+` and its value references the server provided ID of another message:
+
+    +draft/reply=msgid
+
+## Client implementation considerations
+
+This section is non-normative
+
+When displaying replies, take care with the chronology of messages. Clients might choose to display a reply message adjacent to its parent, to make a "thread" apparent. This might work well when the messages are close together in the message history, but could cause problems if there have been several intervening messages in the mean time. People following the conversation may not see a reply if it's hoisted too far into the backlog.
+
+In this situation, it might make more sense to leave the reply in place chronologically, but provide a way to jump to the original message instead.
+
+## Examples
+
+In this example, a `PRIVMSG` is sent to a channel with an ID provided by the server. A client sends a reply to this message and the server sends an echo-message back to the client.
+
+    S: @draft/msgid=123 :nick!user@host PRIVMSG #channel :Hello!
+    C: @+draft/reply=123 :nick2!user2@host2 PRIVMSG #channel :Hello to you!
+    S: @draft/msgid=456;+draft/reply=abc :nick2!user2@host2 PRIVMSG #channel :Hello to you!