You can search for identifiers within the package.
in-package search v0.2.0
module R : sig ... end
val trim : string -> string
val parse : ?recode: (?source:[ `ISO_8859_1 | `UTF_16 | `UTF_16BE | `UTF_16LE | `UTF_8 ] -> string -> string) -> R.t -> (string * string) list
Parse ID3v1 tags.
val parse_file : string -> (string * string) list