+ # allow users to specify articles to refetch
+ # cf. https://tools.ietf.org/id/draft-gilman-news-url-01.txt
+ # nntp://example.com/inbox.foo/$num_a-$num_b
+ $beg = $num_a if defined($num_a) && $num_a > $beg && $num_a <= $end;
+ $end = $num_b if defined($num_b) && $num_b >= $beg && $num_b < $end;
+ $end = $beg if defined($num_a) && !defined($num_b);