@ On page 6,
in the first display both instances of fancy script \B should be plain B
(it’s a single block, not the collection of all blocks);
and on page 7, part (i) of Theorem 1.21 should have
*n* = *k* − λ*k*.

@ On page 11, the reference to (1.7) preceding the statement of
Proposition 1.33 should be to (1.8); Proposition 1.34 should really be
Hughes’ 1961 result that *n* is in {2,4,10},
because we do not yet know that *n*=4 works,
and will not prove that *n*=10 doesn’t occur.

@ The intersection triangle on page 87 for this Steiner system (Table 6.1) should have 3,2,3 in the middle of the bottom row, not 2,3,2.

@ Not an error, but an unfortunate bit of notation:
in the proof of Proposition 1.48 on page 18, please change
*n _{i}* to

@ On page 21, the next-to-last line should have “in accordance with (1.52)”, not (1.42). [Noted by Nathan Kaplan, who also lists a few apparent typos in chapters 4 and 5, which we won’t cover in this class.]