NNTP proxy based on AbstractNntpProxy, permitting only a minimal set of commands to be used. All known possible responses are enabled. The following commands are permitted: ARTICLE; BODY; HEAD; DATE; STAT; GROUP; LAST; LIST; NEWGROUPS; NEWNEWS; NEXT; QUIT; LIST ACTIVE; LIST ACTIVE.TIMES; LIST DISTRIBUTIONS; LIST DISTRIB.PATS; LIST NEWSGROUPS; LIST OVERVIEW.FMT; LIST NEWSGROUPS; LIST SUBSCRIPTIONS; LIST MOTD; LISTGROUP; XGTITLE; XHDR; XOVER; DATE; AUTHINFO USER; AUTHINFO PASS; MODE READER; HELP; IHAVE; POST; SLAVE; XINDEX; XPAT; XROVER; AUTHINFO SIMPLE; LIST EXTENSIONS. All other commands are rejected.