For example, let's say you archive your favorite newsgroup and now you want to know what that loser flaming you said when he was younger and even more clueless. In this case, you search for name[from](Flaming Loser) and put into grazer section of locus.opt
interval_stop_file = "/docdir/file-with-first-message-of-this-year"and optionally
stop_is_in_interval = noso that the search is restricted to previous years. Other relevant options are analogical.
BTW, if this feels like a kludge to you, I must agree. Hovewer, since somebody wanted something like that... :-)