With certain justified exceptions, for instance ``Klausur''. Ask for this exceptions, as they must be granted by us. Just not showing up and the rest of the groups tells us at showtime, is not enough.
Note that for the various java lib's there's a little confusions concerning the numbers (and file names) as some of the jar files which are offered for download at the download space of the java group are just duplicates (with the same version number, sometimes different names??) of the jars, which are installed anyway on snert as part of tomcat. One should base the tool on the official ones, as part of the chosen tomcat installation. Everything else invites trouble.