     The Tree Display

     When reading a threaded newsgroup, trn displays a character representa-
     tion of the article tree in the upper right corner of the header.  For
     example, consider the following display:

         (1)+-(1)--(2)--[2]
            |-(1)+-<3>
            |    \-[1]
            \-(1)+-[1]--[1]
                 \-[1]

     This tree represents an initial article that has three direct replies
     (the second column with three (1)'s).  Each reply has further replies
     branching off from them.  In two cases the subject line was altered in
     the reply, as indicated by the increasing numbers.

     The third subject is not selected for reading, as indicated by the <>'s.
     Note you can always forcefully visit an unselected article with 'N' and
     'P' as well as the thread-navagation commands (which are typically
     macro'ed to the arrow keys on your keypad).

     When there is only one subject associated with a thread, all the nodes
     are marked with the number 1.  When the first subject change arrives, it
     is marked with the number 2, and so on.  If you were to look at this
     thread in the thread selector, the three subjects associated with it
     would be listed in the same order as the ascending digits.  In those
     rare cases where more than 9 subjects are associated with each thread,
     the nodes are marked with the letters A-Z, and then by a-z.

     The articles that have already been read are enclosed in ()'s, Unread
     articles are displayed in []'s, and unread-but-unselected articles are
     displayed in <>'s.  The currently displayed article has its entire node
     highlighted in the display.  The previously displayed article has only
     its number highlighted.  If the group has not been completely threaded
     yet, some articles will appear as (?) until trn can determine if the
     referenced article truly exists or not.  If you visit such an article
     and wait for trn to finish threading the group, the screen will refresh
     as soon as the presence or absence of the article is determined.

