diff --git a/hooks/subjects.pl b/hooks/subjects.pl
index 75ac74d..f6425e1 100755
--- a/hooks/subjects.pl
+++ b/hooks/subjects.pl
@@ -375,17 +375,22 @@ sub tag_project
 	my $mod = 0;
 	for my $vcs ($dom->documentElement()->getElementsByTagName("vcs"))
 	{
+	    if (! $vcs->hasAttribute("tag") || $vcs->getAttribute("tag") =~ /^(ACU|YAKA)-/) {
+		log ERROR, "Un tag de rendu ne peut pas commencer par ACU- ou YAKA-."; # C'est réservé pour les moulettes
+	    }
+
 	    if (! $vcs->hasAttribute("token"))
 	    {
 		if ($project)
 		{
 		    # Looking for an old token
 		    my @rendus = grep {
-			exists $_->{vcs} and $_->{vcs}{tag} eq $vcs->hasAttribute("tag");
+			exists $_->{vcs} and $_->{vcs}{tag} eq $vcs->getAttribute("tag");
 		    } @{ $project->{submissions} };
 
-		    if (@rendus == 1) {
-			log INFO, "Use existing token: ".$rendus[0]->{vcs}{token};
+		    if (@rendus == 1)
+		    {
+			log DEBUG, "Use existing token: ".$rendus[0]->{vcs}{token};
 			$vcs->setAttribute("token", substr($rendus[0]->{vcs}{token}, 2, 23));
 			$mod = 1;
 			next;