X-Git-Url: https://code.citadel.org/?a=blobdiff_plain;f=citadel%2Ftechdoc%2Fprotocol.txt;h=0c69ad7c4da9d917a1c016b7a787bf2afe16f316;hb=db4bd92400cbe8149f33991e98fd58d20c088736;hp=7dfcf40246c88165accbb7598d77a3c7b1c62c25;hpb=15d8ce26425bebfe4a4df12e25f6387714ee5500;p=citadel.git

diff --git a/citadel/techdoc/protocol.txt b/citadel/techdoc/protocol.txt
index 7dfcf4024..0c69ad7c4 100644
--- a/citadel/techdoc/protocol.txt
+++ b/citadel/techdoc/protocol.txt
@@ -1877,6 +1877,15 @@ will output RFC822-like MIME part headers such as "Content-type:" and
 "Content-length:".  MIME formats are chosen and/or converted based on the
 client's preferred format settings, which are set using the MSGP command,
 described below.
+ 
+ The MSG4 command also accepts an optional second argument, which may be the
+MIME part specifier of an encapsulated message/rfc822 message.  This is useful
+for fetching the encapsulated message instead of the top-level message, for
+example, when someone has forwarded a message as an attachment.  Note that the
+only way for the client to know the part specifier is to fetch the top-level
+message and then look for attachments of type message/rfc822, and then call
+MSG4 again with that part specifier.
+