Structures Preserved by Consistently Graded Lie Superalgebras

I construct systems of generalized Pfaff equations (of the form α = 0, α some differential forms), preserved by the exceptional Lie superalgebras ksle(5|10), vle(3|6) and mb(3|8). This yields an intrinsic geometric definition of these algebras. The analogous construction for the contact superalgebra k(1|m) (a.k.a. the centerless N = m superconformal algebra) is reviewed.