From bc8dd57236bdd76549a5453a5e15c9c95c5dcab5 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Mon, 4 Sep 2017 08:15:41 +0200
Subject: [PATCH] doc/protocol.xml: document status/volume=-1

Closes #107
---
 doc/protocol.xml | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/doc/protocol.xml b/doc/protocol.xml
index dca8a75bb..4b9a4c95a 100644
--- a/doc/protocol.xml
+++ b/doc/protocol.xml
@@ -445,7 +445,9 @@
               <listitem>
                 <para>
                   <varname>volume</varname>:
-                  <returnvalue>0-100</returnvalue>
+                  <returnvalue>0-100</returnvalue> or
+                  <returnvalue>-1</returnvalue> if the volume cannot
+                  be determined
                 </para>
               </listitem>
               <listitem>