It would be nice to attach an odoc comment to a function parameter rather than having to mention each parameter in the comment for the whole function. Something like:

(** Do the special thing. *)
val do_it :
  (** What does the thing *)
  t ->
  (** What the thing is done to *)
  target:t ->
  (** The special sauce to use *)
  sauce:Sauce.t ->
  unit

(There's already a wrinkle in that putting the arrows at the starts of lines would would probably cause the comments to attach to different parameters.)