Matt Couchman asks about the rules for the contraction:
Tag_heading ----> n (where n is the no. of items)
in the tree display.
Currently the rule is that thing are contracted by default if there
are more than 5 items in the column to the right, or more than 3 items
if the top item would be displayed using a -T derived name, rather
than it's default name (e.g. the Title of a paper).
This rule is not under user control. It probably should be in some
fashion. I am interested in collecting ideas about the most useful
ways to do this, always rememberng that we would like to avoid a lot
of extra complexity for both user and programmer, and that there is no
implied promise that I will implement any of these ideas!