Tensoring irreducible $B$-series representations/ Type B Littlewood-Richardson

Littelmann used standard monomial theory to give a unified Littlewood–Richardson rule for the simple reductive algebraic groups of types $A$, $B$, $C$ and $D$ (and some others) in which the coefficients enumerate certain generalized standard tableaux. See (a) in the theorem on page 346 of Littlemann's paper, A generalization of the Littlewood-Richardson rule., J. Alg. 130 (1990) 328–368.