meaning of thread tree marking

["Andrei A. Voropaev" <avorop@xxxxxxx>]

Hi!

I've noticed that threads can be drawn slightly different. See below for
example.

      3 r + 05/09 Gordon Seipold  (  49) AW: access
      4 r + 05/09 Gordon Seipold  (  84) |*>
      5   + 01/10 Gordon Seipold  (  43) `*>
      9   T 16/09 David W. Lewis  (  48) RE: connectivity
->   10 r T 23/09 Chifu Valerian  (  25) `->

The first thread has '*' before '>' and second thead has '-'. I tried to
find clarification in the manual.txt but failed. Anyone can tell me what
is the meaning of that '*'?

--
Andrei