Codewords for Projective Planes from Sets of Type ( s, t)

Abstract

Let Π * be a projective plane of order n 2 having a Baer subplane Π, and let C be the code of Π * over a prime field F p , where p divides n . If Π contains a set K of type ( s, t), then it is shown that the incidence vectors of certain sets of points defined through K are, subject to some congruence relations, in C ⊥ , and sometimes in C ∩ C ⊥ .