  We study the discrete transformations of four-valent braid excitations of
framed spin networks embedded in a topological three-manifold. We show that
four-valent braids allow seven and only seven discrete transformations. These
transformations can be uniquely mapped to C, P, T, and their products. Each CPT
multiplet of actively-interacting braids is found to be uniquely characterized
by a non-negative integer. Finally, braid interactions turn out to be invariant
under C, P, and T.
