You can search for identifiers within the package.
in-package search v0.2.0
module type S1 = sig ... end
module Make1 (Kernel : OBMonad.Kernel1) : S1 with type 'a t = 'a Kernel.t
module type S2 = sig ... end
module Make2 (Kernel : OBMonad.Kernel2) : S2 with type ('a, 'b) t = ('a, 'b) Kernel.t