After a lengthy computer investigation into Steiner systems
S(2,4,25) (the same thing as a 2-(25,4,1) design), I can now announce
that they have been completely classified. The result is that there are
exactly 18 such Steiner systems, 16 of which have a non-trivial
automorphism group and were already known [1]. The new part of my
investigation was the complete determination of those with a
**trivial** automorphism group. If you would like a copy of these
18 designs you can get them from S(2,4,25)
(in zero-one form).
These results were announced in [2].

[1] E S Kramer, S S Maglivers and R Mathon, The Steiner Systems S(2,4,25)
with Nontrivial Automorphism Group, *J. Discr. Math.* **77** (1989),
pp 137-157.

[2] E Spence, The Complete Classification of Steiner Systems S(2,4,25)
*Journ. Comb. Designs* **4** (1996), no. 4, 295-300.