Abstract
In selective multiquantum N.M.R. specific transitions in the (2I+1) manifold of levels are excited. In order to treat this problem the concept of multiplet spin IM is introduced which takes all groups of closest (2IM +1) multiplets out of the (2I+1) levels. The theory of multiplet spin is developed and related to the fictitious spin-1/2 formalism and the multipole approach.