diff --git a/interface.go b/interface.go
index c7ebcb4e3..0567b89d3 100644
--- a/interface.go
+++ b/interface.go
@@ -32,7 +32,7 @@ type Session interface {
 	OpenStreamSync() (Stream, error)
 	// RemoteAddr returns the address of the peer.
 	RemoteAddr() net.Addr
-	// Close closes the connection. An error value of nil is allowed.
+	// Close closes the connection. The error will be sent to the remote peer in a CONNECTION_CLOSE frame. An error value of nil is allowed and will cause a normal PeerGoingAway to be sent.
 	Close(error) error
 }
 
@@ -54,11 +54,12 @@ const (
 type ConnStateCallback func(Session, ConnState)
 
 // Config contains all configuration data needed for a QUIC server or client.
+// More config parameters (such as timeouts) will be added soon, see e.g. https://github.com/lucas-clemente/quic-go/issues/441.
 type Config struct {
 	TLSConfig *tls.Config
 	// ConnStateCallback will be called when the QUIC version is successfully negotiated or when the encryption level changes.
 	// If this field is not set, the Dial functions will return only when the connection is forward secure.
-	// The callback may be called in a separate goroutine.
+	// Callbacks have to be thread-safe, since they might be called in separate goroutines.
 	ConnState ConnStateCallback
 }
 
diff --git a/public_header.go b/public_header.go
index e8b26e56b..f68496b75 100644
--- a/public_header.go
+++ b/public_header.go
@@ -17,7 +17,7 @@ var (
 	errGetLengthNotForVersionNegotiation = errors.New("PublicHeader: GetLength cannot be called for VersionNegotiation packets")
 )
 
-// The PublicHeader of a QUIC packet.
+// The PublicHeader of a QUIC packet. Warning: This struct should not be considered stable and will change soon.
 type PublicHeader struct {
 	Raw                  []byte
 	ConnectionID         protocol.ConnectionID