Codes of Desarguesian projective planes of even order, projective triads and (q+t,t)-arcs of type (0,2,t)

We study the binary dual codes associated with Desarguesian projective planes PG(2,q), with q=h2, and their links with (q+t,t)-arcs of type (0,2,t), by considering the elements of Fq as binary h-tuples. Using a correspondence between (q+t,t)-arcs of type (0,2,t) and projective triads in PG(2,q), q even, we present an alternative proof of the classification result on projective triads. We construct a new infinite family of (q+t,t)-arcs of type (0,2,t) with , using a particular form of the primitive polynomial of the field Fq.