Index: src/XMPPConnection.h
==================================================================
--- src/XMPPConnection.h
+++ src/XMPPConnection.h
@@ -147,19 +147,20 @@
 	OFString *username, *password, *server, *resource;
 	OFString *privateKeyFile, *certificateFile;
 	OFString *domain, *domainToASCII;
 	XMPPJID *JID;
 	uint16_t port;
+	id <XMPPStorage> dataStorage;
 	OFString *language;
 	XMPPMulticastDelegate *delegates;
 	OFMutableDictionary *callbacks;
 	XMPPAuthenticator *authModule;
 	BOOL streamOpen;
 	BOOL needsSession;
 	BOOL encryptionRequired, encrypted;
+	BOOL rosterVersioningSupported;
 	unsigned int lastID;
-	id <XMPPStorage> dataStorage;
 /// \endcond
 }
 
 #ifdef OF_HAVE_PROPERTIES
 /// \brief The username to use for authentication
@@ -184,18 +185,20 @@
 @property (copy) OFString *certificateFile;
 /// \brief The JID the server assigned to the connection after binding
 @property (copy, readonly) XMPPJID *JID;
 /// \brief The port to connect to
 @property uint16_t port;
+/// \brief An object for data storage, conforming to the XMPPStorage protocol
+@property (assign) id <XMPPStorage> dataStorage;
 /// \brief The socket used for the connection
 @property (readonly, retain, getter=socket) OFTCPSocket *sock;
 /// \brief Whether encryption is required
 @property BOOL encryptionRequired;
 /// \brief Whether the connection is encrypted
 @property (readonly) BOOL encrypted;
-/// \brief An object for data storage, conforming to the XMPPStorage protocol
-@property (assign) id <XMPPStorage> dataStorage;
+/// \brief Whether roster versioning is supported
+@property (readonly) BOOL rosterVersioningSupported;
 #endif
 
 /**
  * \brief Creates a new autoreleased XMPPConnection.
  *

Index: src/XMPPConnection.m
==================================================================
--- src/XMPPConnection.m
+++ src/XMPPConnection.m
@@ -347,10 +347,15 @@
 
 - (BOOL)streamOpen
 {
 	return streamOpen;
 }
+
+- (BOOL)rosterVersioningSupported
+{
+	return rosterVersioningSupported;
+}
 
 - (BOOL)checkCertificateAndGetReason: (OFString**)reason
 {
 	X509Certificate *cert;
 	OFDictionary *SANs;
@@ -842,10 +847,14 @@
 	}
 
 	if (encryptionRequired && !encrypted)
 		/* TODO: Find/create an exception to throw here */
 		@throw [OFException exceptionWithClass: isa];
+
+	if ([element elementForName: @"ver"
+			  namespace: XMPP_NS_ROSTERVER] != nil)
+		rosterVersioningSupported = YES;
 
 	if (mechs != nil) {
 		OFEnumerator *enumerator;
 		OFXMLElement *mech;
 

Index: src/namespaces.h
==================================================================
--- src/namespaces.h
+++ src/namespaces.h
@@ -21,11 +21,12 @@
  */
 
 #define XMPP_NS_BIND @"urn:ietf:params:xml:ns:xmpp-bind"
 #define XMPP_NS_CLIENT @"jabber:client"
 #define XMPP_NS_ROSTER @"jabber:iq:roster"
+#define XMPP_NS_ROSTERVER @"urn:xmpp:features:rosterver"
 #define XMPP_NS_SASL @"urn:ietf:params:xml:ns:xmpp-sasl"
+#define XMPP_NS_SESSION @"urn:ietf:params:xml:ns:xmpp-session"
 #define XMPP_NS_STARTTLS @"urn:ietf:params:xml:ns:xmpp-tls"
 #define XMPP_NS_STANZAS @"urn:ietf:params:xml:ns:xmpp-stanzas"
-#define XMPP_NS_SESSION @"urn:ietf:params:xml:ns:xmpp-session"
-#define XMPP_NS_XMPP_STREAM @"urn:ietf:params:xml:ns:xmpp-streams"
 #define XMPP_NS_STREAM @"http://etherx.jabber.org/streams"
+#define XMPP_NS_XMPP_STREAM @"urn:ietf:params:xml:ns:xmpp-streams"