You can search for identifiers within the package.
in-package search v0.2.0
type tbl = (int * type_id, Obj.t) Hashtbl.t
val create : int -> ('a, 'b) Hashtbl.t
val clear : ('a, 'b) Hashtbl.t -> unit
val put : ('a, 'b) Hashtbl.t -> 'a -> 'b -> unit
val get : ('a, 'b) Hashtbl.t -> 'a -> 'b