Reddit_api_kernel.UsernameUsername is a string identifier module that does some normalization:
include Core.Identifiable.Sval bin_size_t : t Bin_prot__.Size.sizerval bin_write_t : t Bin_prot__.Write.writerval bin_read_t : t Bin_prot__.Read.readerval __bin_read_t__ : (int -> t) Bin_prot__.Read.readerval bin_writer_t : t Bin_prot__.Type_class.writerval bin_reader_t : t Bin_prot__.Type_class.readerval bin_t : t Bin_prot__.Type_class.tval t_of_sexp : Sexplib0__.Sexp.t -> tval sexp_of_t : t -> Sexplib0.Sexp.tval of_string : string -> tval to_string : t -> stringval pp : Base__.Formatter.t -> t -> unitmodule Replace_polymorphic_compare : sig ... endval comparator : (t, comparator_witness) Core__Comparator.comparatormodule Map : sig ... endmodule Set : sig ... endval hash_fold_t : t Base__Ppx_hash_lib.hash_foldval hash : t -> Base__Ppx_hash_lib.Std.Hash.hash_valueval hashable : t Core__.Hashtbl.Hashable.tmodule Table : sig ... endmodule Hash_set : sig ... endmodule Hash_queue : sig ... endval of_string_or_deleted : string -> t option