“…This type of models became of special interest lately due to the many desirable featured exhibited, like the dual formulation of field theories of spin two or higher [7,8,9,10,11,12], the impossibility of consistent cross-interactions in the dual formulation of linearized gravity [13] or a Lagrangian first-order approach [14,15] to some classes of massless or partially massive mixed symmetry-type tensor gauge fields, suggestively resembling to the tetrad formalism of General Relativity. A basic problem involving mixed symmetrytype tensor fields is the approach to their local BRST cohomology, since it is helpful at solving many Lagrangian and Hamiltonian aspects, like, for instance the determination of their consistent interactions [16] with higher-spin gauge theories [6,18,19,20,21,22,30,31]. The present paper proposes the investigation of the basic cohomological ingredients involved in the structure of the co-cycles from the local BRST cohomology for a free, massless tensor gauge field t µ 1 ···µ k |ν 1 ···ν k that transforms in an irreducible representation of GL (D, R), corresponding to a rectangular, two-column Young diagram with k > 2 rows.…”