Calderbank, AR, *Inequalities for quasi-symmetric designs*,
Journal of Combinatorial Theory, Series A, vol. 48 no. 1
(1988),
pp. 53-64 .
**Abstract:**

*A 2-design is said to be quasi-symmetric if there are two block intersection sizes. We obtain inequalities satisfied by the parameters of a quasi-symmetric design using linear programming techniques. The same methods apply to codes with covering radius 2 with the property that the number of codewords at distance 2 from a given vector ν depends on the distance of ν from the code. © 1988.*