diff -r f95894dd5aeb -r fde8ca72dcd4 ProtocolNumbers.wiki
--- a/ProtocolNumbers.wiki	Fri Sep 07 12:25:32 2018 +0100
+++ b/ProtocolNumbers.wiki	Fri Sep 07 12:33:35 2018 +0100
@@ -2,7 +2,13 @@
 
 = Protocol numbers =
 
-Hedgewars uses *protocol numbers* to encode different Hedgewars versions. The protocol number is mainly used on the server.
+Hedgewars uses *protocol numbers* to encode different Hedgewars versions. The protocol number is mainly used on the server. The protocol number is important because players have to be on the same version to play together.
+
+In Hedgewars, all versions without a “-dev” are called “stable” releases. These are the releases you find on the official Download page. Note that for some releases, the protocol number is not increased. This is the case for backwards-compatible bugfix releases. Thus, protocol number 55 is valid for 0.9.24 and 0.9.24.1.
+
+A “-dev” in the version number means it is a version in *dev*elopment. This is not really a specific version, more like a shorthand. A version X.Y.Z-dev means that it could be a build of any commit after the previous stable relese but before the next stable release X.Y.Z.
+
+E.g. the development version before 0.9.24 is 0.9.24-dev.
 
 == List of protocol numbers ==