Codes from planar near rings

It is well known that error-correcting codes give rise to tactical configurations. Conversely, each such configuration determines four different codes, the codewords being the rows or the columns of the incidence matrix A of the tactical configuration, or the linear hulls generated by the rows or the columns of A. These codes, in particular if the tactical configuration is a block design, are investigated. Several of these codes turn out to be `almost perfect´. The special case in which the balanced incomplete block designs are constructed from planar near rings is also investigated. Special classes of planar near rings (the `circular´ ones) that might be especially useful (see J.R. Clay, 1987 and 1988) are investigated