The Gleason-Pierce theorem characterizes those fields for which formal
ly self-dual divisible codes can exist. The ideas underlying the proof
of the theorem yield necessary conditions on whether a solution to th
e MacWilliams identity can be the weight distribution of a linear code
. Consequences of this result are an algebraic proof of the non-existe
nce of an [16, 8, 6] f.s.d. binary even code, restrictions on distribu
tion of cosets of codes, and occasional sharpening of upper bounds on
the covering radius. (C) 1994 Academic Press, Inc.