[horde] What is horde_histories for?

[Otto Stolz]

PS.

my beta-test version (Horde 3.1.3 + Imp 4.1.3 + Turba 2.1.3,
with data imported from the old production version Horde 2.2
+ IMP 3.2 + Turba 1.2) has three tables that are not created
by either horde/scripts/sql/create.mysql.sql or
horde/turba/scripts/sql/turba_objects.mysql.sql, viz.
- horde_categories
- horde_datatree_seq
- horde_histories_seq

What about these? Are they no longer required? Or will they
be created, on demand?

Thanks for any insight.

Best wishes,
   Otto Stolz