This web site is mainly devoted to BIBDs, Nested BIBDs, OBIBDs and Nested OBIBDs. It will include informal constructions and properties of these designs, examples, and non-exhaustive lists of designs, from searches (including the order of the automorphism group, where possible.) It is intended to reflect my own interests, and not as a rival to any other such: it is not a didactic tool, things will be included or excluded as the spirit moves me.

In many cases, I do not know whether the results given here are original or not, as I live in a very complicated world: if anyone objects that he/she should be given the credit for something given here, let him/her email me with the details and I will try to do him/her justice.

Some references are given, but I cannot guarantee that all relevant ones are listed.

I intend now to tidy up some of the investigations, adding in some new stuff, and removing some of the less useful comments from otherwise valid pages, and the less useful pages.


The automorphism groups were calculated with the aid of the set of procedures nauty (the previous version), downloadable from here, written by B.D.McKay. Responsibility for the correctness of the results, as of everything else, rests with me.

Details of groups are as given in GAP. Again, any errors arising in their use are my responsibility.

I removed the email link because I was getting so much junk email (based, I assume, on automated scanners). For an experimental period, I now give not one, but two: and

Site last updated: 3rd January 2012

By D.H.Rees