diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4309a17924a..83c31f3c361 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -82,6 +82,7 @@
 
 #### :house: Internal
 
+- Remove OCaml leftovers: unused warning numbers, the `Record_float_unused` representation, the `ns.braces` attribute name and unused `Ast_helper` functions. https://github.com/rescript-lang/rescript/pull/8805
 - Remove the S-expression parsetree printer (`res_parser -print sexp`). https://github.com/rescript-lang/rescript/pull/8803
 - Use one set of OCaml warning flags for the whole repository, including the editor analysis and tools. https://github.com/rescript-lang/rescript/pull/8796
 - Remove the unused `Packed` and `Partial_class_expr` constructors from the `.cmt` format and bump its magic number. https://github.com/rescript-lang/rescript/pull/8793
diff --git a/compiler/ext/bsc_warnings.ml b/compiler/ext/bsc_warnings.ml
index 83ec4124273..955f9da9be2 100644
--- a/compiler/ext/bsc_warnings.ml
+++ b/compiler/ext/bsc_warnings.ml
@@ -41,12 +41,10 @@
      type b = A | B | C
    ]}
 
-   - 50 Unexpected documentation comment.
-
    - 102 Bs_polymorphic_comparison.
 *)
 (* If you change this, don't forget to adapt docs/docson/build-schema.json as well. *)
-let defaults_w = "+a-4-9-20-41-50-102"
+let defaults_w = "+a-4-9-20-41-102"
 
-let defaults_warn_error = "-a+5+6+101+109"
+let defaults_warn_error = "-a+5+101+109"
 (*TODO: add +10*)
diff --git a/compiler/ext/config.ml b/compiler/ext/config.ml
index 7644a6cb98d..432d1e3b25a 100644
--- a/compiler/ext/config.ml
+++ b/compiler/ext/config.ml
@@ -1,4 +1,4 @@
-let cmi_magic_number = "Caml1999I035"
+let cmi_magic_number = "Caml1999I036"
 
 (* Magic numbers for marshaled values of the *current* parsetree, whose layout
    changes across compiler versions. *)
@@ -13,6 +13,6 @@ and ast0_impl_magic_number = "Caml1999M022"
 
 and ast0_intf_magic_number = "Caml1999N022"
 
-and cmt_magic_number = "Caml1999T042"
+and cmt_magic_number = "Caml1999T043"
 
 let load_path = ref ([] : string list)
diff --git a/compiler/ext/warnings.ml b/compiler/ext/warnings.ml
index 64fd263327b..3bb428d2683 100644
--- a/compiler/ext/warnings.ml
+++ b/compiler/ext/warnings.ml
@@ -140,7 +140,7 @@ let letter_all =
 let letter = function
   | 'a' -> letter_all
   | 'b' -> []
-  | 'c' -> [1; 2]
+  | 'c' -> []
   | 'd' -> [3]
   | 'e' -> [4]
   | 'f' -> [5]
@@ -148,20 +148,20 @@ let letter = function
   | 'h' -> []
   | 'i' -> []
   | 'j' -> []
-  | 'k' -> [32; 33; 34; 35; 36; 37; 38; 39]
-  | 'l' -> [6]
-  | 'm' -> [7]
+  | 'k' -> [32; 33; 34; 35; 37; 38; 39]
+  | 'l' -> []
+  | 'm' -> []
   | 'n' -> []
   | 'o' -> []
   | 'p' -> [8]
   | 'q' -> []
   | 'r' -> [9]
-  | 's' -> [10]
+  | 's' -> []
   | 't' -> []
   | 'u' -> [11; 12]
-  | 'v' -> [13]
+  | 'v' -> []
   | 'w' -> []
-  | 'x' -> [14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 30]
+  | 'x' -> [20; 21; 22; 23; 30]
   | 'y' -> [26]
   | 'z' -> [27]
   | _ -> assert false
@@ -505,14 +505,10 @@ let descriptions =
     (9, "Missing fields in a record pattern.");
     (11, "Redundant case in a pattern matching (unused match case).");
     (12, "Redundant sub-pattern in a pattern-matching.");
-    (17, "Undeclared virtual method.");
-    (18, "Non-principal type.");
-    (19, "Type without principality.");
     (20, "Unused function argument.");
     (21, "Non-returning statement.");
     (22, "Preprocessor warning.");
     (23, "Useless record \"with\" clause.");
-    (25, "Deprecated: now part of warning 8.");
     ( 26,
       "Suspicious unused variable: unused variable that is bound\n\
       \    with \"let\" or \"as\", and doesn't start with an underscore (\"_\")\n\
@@ -525,12 +521,10 @@ let descriptions =
     ( 30,
       "Two labels or constructors of the same name are defined in two\n\
       \    mutually recursive types." );
-    (31, "A module is linked twice in the same executable.");
     (32, "Unused value declaration.");
     (33, "Unused open statement.");
     (34, "Unused type declaration.");
     (35, "Unused for-loop index.");
-    (36, "Unused ancestor variable.");
     (37, "Unused constructor.");
     (38, "Unused extension constructor.");
     (39, "Unused rec flag.");
@@ -538,16 +532,13 @@ let descriptions =
     (43, "Nonoptional label applied as optional.");
     (44, "Open statement shadows an already defined identifier.");
     (45, "Open statement shadows an already defined label or constructor.");
-    (46, "Error in environment variable.");
     (47, "Illegal attribute payload.");
     (49, "Absent cmi file when looking up module alias.");
     (52, "Fragile constant pattern.");
     (53, "Attribute cannot appear in this context");
     (54, "Attribute used more than once on an expression");
-    (55, "Inlining impossible");
     (56, "Unreachable case in a pattern-matching (based on type information).");
     (57, "Ambiguous or-pattern variables under guard");
-    (59, "Assignment to non-mutable value");
     (60, "Unused module declaration");
     (62, "Type constraint on GADT type declaration");
     (101, "Unused bs attributes");
diff --git a/compiler/gentype/translate_type_declarations.ml b/compiler/gentype/translate_type_declarations.ml
index ea6052600cc..c7dfb2f69f7 100644
--- a/compiler/gentype/translate_type_declarations.ml
+++ b/compiler/gentype/translate_type_declarations.ml
@@ -230,7 +230,6 @@ let traslate_declaration_kind ~config ~loc ~output_file_relative ~resolver
       match representation with
       | Record_unboxed _ -> true
       | Record_regular | Record_inlined _ | Record_extension -> false
-      | Record_float_unused -> assert false
     in
     let {Translate_type_expr_from_types.dependencies; type_} =
       label_declarations |> translate_label_declarations ~unboxed
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index 43fd072646e..162c6753f7e 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -29,12 +29,6 @@ let default_loc = ref Location.none
 module Const = struct
   let integer ?suffix i = Pconst_integer (i, suffix)
   let int ?suffix i = integer ?suffix (string_of_int i)
-  let int32 ?(suffix = 'l') i = integer ~suffix (Int32.to_string i)
-  let int64 ?(suffix = 'L') i = integer ~suffix (Int64.to_string i)
-  let float ?suffix f = Pconst_float (f, suffix)
-  let char c =
-    let semantic = Char.code c in
-    Pconst_char {source = String_literal.encode_char_source semantic; semantic}
   let string semantic =
     Pconst_string (String_literal.string_from_semantic semantic)
 end
@@ -42,7 +36,6 @@ end
 module Typ = struct
   let mk ?(loc = !default_loc) ?(attrs = []) d =
     {ptyp_desc = d; ptyp_loc = loc; ptyp_attributes = attrs}
-  let attr d a = {d with ptyp_attributes = d.ptyp_attributes @ [a]}
 
   let any ?loc ?attrs () = mk ?loc ?attrs Ptyp_any
   let var ?loc ?attrs a = mk ?loc ?attrs (Ptyp_var a)
@@ -127,7 +120,6 @@ end
 module Pat = struct
   let mk ?(loc = !default_loc) ?(attrs = []) d =
     {ppat_desc = d; ppat_loc = loc; ppat_attributes = attrs}
-  let attr d a = {d with ppat_attributes = d.ppat_attributes @ [a]}
 
   let any ?loc ?attrs () = mk ?loc ?attrs Ppat_any
   let var ?loc ?attrs a = mk ?loc ?attrs (Ppat_var a)
@@ -152,7 +144,6 @@ end
 module Exp = struct
   let mk ?(loc = !default_loc) ?(attrs = []) d =
     {pexp_desc = d; pexp_loc = loc; pexp_attributes = attrs}
-  let attr d a = {d with pexp_attributes = d.pexp_attributes @ [a]}
 
   let braces ?(attrs = []) ~braces_loc e =
     mk ~loc:e.pexp_loc ~attrs (Pexp_braces {expr = e; braces_loc})
@@ -267,7 +258,6 @@ end
 module Mty = struct
   let mk ?(loc = !default_loc) ?(attrs = []) d =
     {pmty_desc = d; pmty_loc = loc; pmty_attributes = attrs}
-  let attr d a = {d with pmty_attributes = d.pmty_attributes @ [a]}
 
   let ident ?loc ?attrs a = mk ?loc ?attrs (Pmty_ident a)
   let alias ?loc ?attrs a = mk ?loc ?attrs (Pmty_alias a)
@@ -281,7 +271,6 @@ end
 module Mod = struct
   let mk ?(loc = !default_loc) ?(attrs = []) d =
     {pmod_desc = d; pmod_loc = loc; pmod_attributes = attrs}
-  let attr d a = {d with pmod_attributes = d.pmod_attributes @ [a]}
 
   let ident ?loc ?attrs x = mk ?loc ?attrs (Pmod_ident x)
   let structure ?loc ?attrs x = mk ?loc ?attrs (Pmod_structure x)
@@ -562,23 +551,6 @@ module Te = struct
       pext_loc = loc;
       pext_attributes = attrs;
     }
-
-  let decl ?(loc = !default_loc) ?(attrs = []) ?(args = Pcstr_tuple []) ?res
-      name =
-    {
-      pext_name = name;
-      pext_kind = Pext_decl (args, res);
-      pext_loc = loc;
-      pext_attributes = attrs;
-    }
-
-  let rebind ?(loc = !default_loc) ?(attrs = []) name lid =
-    {
-      pext_name = name;
-      pext_kind = Pext_rebind lid;
-      pext_loc = loc;
-      pext_attributes = attrs;
-    }
 end
 
 module Jsx = struct
diff --git a/compiler/ml/ast_helper.mli b/compiler/ml/ast_helper.mli
index bf1dad721a7..19d502945e1 100644
--- a/compiler/ml/ast_helper.mli
+++ b/compiler/ml/ast_helper.mli
@@ -28,13 +28,9 @@ type attrs = attribute list
 (** {1 Constants} *)
 
 module Const : sig
-  val char : char -> constant
   val string : string -> constant
   val integer : ?suffix:char -> string -> constant
   val int : ?suffix:char -> int -> constant
-  val int32 : ?suffix:char -> int32 -> constant
-  val int64 : ?suffix:char -> int64 -> constant
-  val float : ?suffix:char -> string -> constant
 end
 
 (** {1 Core language} *)
@@ -42,7 +38,6 @@ end
 (** Type expressions *)
 module Typ : sig
   val mk : ?loc:loc -> ?attrs:attrs -> core_type_desc -> core_type
-  val attr : core_type -> attribute -> core_type
 
   val any : ?loc:loc -> ?attrs:attrs -> unit -> core_type
   val var : ?loc:loc -> ?attrs:attrs -> string -> core_type
@@ -81,7 +76,6 @@ end
 (** Patterns *)
 module Pat : sig
   val mk : ?loc:loc -> ?attrs:attrs -> pattern_desc -> pattern
-  val attr : pattern -> attribute -> pattern
 
   val any : ?loc:loc -> ?attrs:attrs -> unit -> pattern
   val var : ?loc:loc -> ?attrs:attrs -> str -> pattern
@@ -117,7 +111,6 @@ end
 (** Expressions *)
 module Exp : sig
   val mk : ?loc:loc -> ?attrs:attrs -> expression_desc -> expression
-  val attr : expression -> attribute -> expression
 
   val braces : ?attrs:attrs -> braces_loc:loc -> expression -> expression
   val ident : ?loc:loc -> ?attrs:attrs -> lid -> expression
@@ -358,15 +351,6 @@ module Te : sig
     str ->
     extension_constructor_kind ->
     extension_constructor
-
-  val decl :
-    ?loc:loc ->
-    ?attrs:attrs ->
-    ?args:constructor_arguments ->
-    ?res:core_type ->
-    str ->
-    extension_constructor
-  val rebind : ?loc:loc -> ?attrs:attrs -> str -> lid -> extension_constructor
 end
 
 module Jsx : sig
@@ -379,7 +363,6 @@ end
 (** Module type expressions *)
 module Mty : sig
   val mk : ?loc:loc -> ?attrs:attrs -> module_type_desc -> module_type
-  val attr : module_type -> attribute -> module_type
 
   val ident : ?loc:loc -> ?attrs:attrs -> lid -> module_type
   val alias : ?loc:loc -> ?attrs:attrs -> lid -> module_type
@@ -404,7 +387,6 @@ end
 (** Module expressions *)
 module Mod : sig
   val mk : ?loc:loc -> ?attrs:attrs -> module_expr_desc -> module_expr
-  val attr : module_expr -> attribute -> module_expr
 
   val ident : ?loc:loc -> ?attrs:attrs -> lid -> module_expr
   val structure : ?loc:loc -> ?attrs:attrs -> structure -> module_expr
diff --git a/compiler/ml/ast_mapper_from0.ml b/compiler/ml/ast_mapper_from0.ml
index d44ea4d7d07..810a42dcdb8 100644
--- a/compiler/ml/ast_mapper_from0.ml
+++ b/compiler/ml/ast_mapper_from0.ml
@@ -745,8 +745,7 @@ module E = struct
     in
     let first_wrapper =
       let rec find = function
-        | ({txt = "res.braces" | "ns.braces"; loc}, _) :: _ ->
-          Some (`Braces loc)
+        | ({txt = "res.braces"; loc}, _) :: _ -> Some (`Braces loc)
         | ({txt = "res.await"}, _) :: _ -> Some `Await
         | _ :: rest -> find rest
         | [] -> None
@@ -760,7 +759,7 @@ module E = struct
            | _ -> false ->
       let outer_attrs0, braces_loc, inner_attrs0 =
         let rec split acc = function
-          | ({Location.txt = "res.braces" | "ns.braces"; loc}, _) :: rest ->
+          | ({Location.txt = "res.braces"; loc}, _) :: rest ->
             (List.rev acc, loc, rest)
           | a :: rest -> split (a :: acc) rest
           | [] -> assert false
diff --git a/compiler/ml/matching.ml b/compiler/ml/matching.ml
index dfabf676e2b..ecf81aa544a 100644
--- a/compiler/ml/matching.ml
+++ b/compiler/ml/matching.ml
@@ -1488,7 +1488,6 @@ let make_record_matching loc all_labels def = function
         let lbl = all_labels.(pos) in
         let access =
           match lbl.lbl_repres with
-          | Record_float_unused -> assert false
           | Record_regular ->
             prim
               ~primitive:
diff --git a/compiler/ml/printtyped.ml b/compiler/ml/printtyped.ml
index 73eb6f36bf9..fd0c8e58bd1 100644
--- a/compiler/ml/printtyped.ml
+++ b/compiler/ml/printtyped.ml
@@ -127,7 +127,6 @@ let record_representation i ppf =
   let open Types in
   function
   | Record_regular -> line i ppf "Record_regular\n"
-  | Record_float_unused -> assert false
   | Record_unboxed b -> line i ppf "Record_unboxed %b\n" b
   | Record_inlined {name} -> line i ppf "Record_inlined %s\n" name
   | Record_extension -> line i ppf "Record_extension\n"
diff --git a/compiler/ml/rec_check.ml b/compiler/ml/rec_check.ml
index 30f063e46db..b2e7f2c9244 100644
--- a/compiler/ml/rec_check.ml
+++ b/compiler/ml/rec_check.ml
@@ -292,7 +292,6 @@ let rec expression : Env.env -> Typedtree.expression -> Use.t =
     let use =
       match rep with
       | Record_unboxed _ -> fun x -> x
-      | Record_float_unused -> assert false
       | Record_regular | Record_inlined _ | Record_extension -> Use.guard
     in
     let field env = function
diff --git a/compiler/ml/translcore.ml b/compiler/ml/translcore.ml
index 7ba2099d2d6..a5897de7876 100644
--- a/compiler/ml/translcore.ml
+++ b/compiler/ml/translcore.ml
@@ -1411,7 +1411,6 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.t =
   | Texp_field (arg, _, lbl) -> (
     let targ = transl_exp arg in
     match lbl.lbl_repres with
-    | Record_float_unused -> assert false
     | Record_regular ->
       prim
         ~primitive:
@@ -1432,7 +1431,6 @@ and transl_exp0 (e : Typedtree.expression) : Lambda.t =
   | Texp_setfield (arg, _, lbl, newval) ->
     let access =
       match lbl.lbl_repres with
-      | Record_float_unused -> assert false
       | Record_regular ->
         Psetfield (lbl.lbl_pos, Lambda.fld_record_set lbl.lbl_runtime_name)
       | Record_inlined _ ->
@@ -1768,7 +1766,6 @@ and transl_record loc env fields repres opt_init_expr =
             | Kept _ ->
               let access =
                 match repres with
-                | Record_float_unused -> assert false
                 | Record_regular ->
                   Pfield (i, Lambda.fld_record lbl.lbl_runtime_name)
                 | Record_inlined _ ->
@@ -1793,7 +1790,6 @@ and transl_record loc env fields repres opt_init_expr =
           if mut = Mutable then raise Not_constant;
           let cl = List.map extract_constant ll in
           match repres with
-          | Record_float_unused -> assert false
           | Record_regular ->
             const (Const_block (Lambda.blk_record (field_shape ()) mut, cl))
           | Record_inlined {name; representation} ->
@@ -1823,7 +1819,6 @@ and transl_record loc env fields repres opt_init_expr =
             prim
               ~primitive:(Pmakeblock (Lambda.blk_record (field_shape ()) mut))
               ~args:ll loc
-          | Record_float_unused -> assert false
           | Record_inlined {name; representation} ->
             let runtime =
               match Variant_runtime.representation representation with
@@ -1870,7 +1865,6 @@ and transl_record loc env fields repres opt_init_expr =
         | Overridden (_lid, expr) ->
           let upd =
             match repres with
-            | Record_float_unused -> assert false
             | Record_regular ->
               Psetfield (lbl.lbl_pos, Lambda.fld_record_set lbl.lbl_runtime_name)
             | Record_inlined _ ->
diff --git a/compiler/ml/types.ml b/compiler/ml/types.ml
index 94147e90342..9808899d8fa 100644
--- a/compiler/ml/types.ml
+++ b/compiler/ml/types.ml
@@ -154,7 +154,6 @@ and type_kind =
 
 and record_representation =
   | Record_regular (* All fields are boxed / tagged *)
-  | Record_float_unused (* Was: all fields are floats. Now: unused *)
   | Record_unboxed of bool (* Unboxed single-field record, inlined or not *)
   | Record_inlined of
       (* Inlined record *)
@@ -325,7 +324,6 @@ type label_description = {
 let same_record_representation x y =
   match x with
   | Record_regular -> y = Record_regular
-  | Record_float_unused -> y = Record_float_unused
   | Record_inlined {name} -> (
     match y with
     | Record_inlined y -> name = y.name
diff --git a/compiler/ml/types.mli b/compiler/ml/types.mli
index e8ae34ce2b3..a40961b5d61 100644
--- a/compiler/ml/types.mli
+++ b/compiler/ml/types.mli
@@ -251,7 +251,6 @@ and type_kind =
 
 and record_representation =
   | Record_regular (* All fields are boxed / tagged *)
-  | Record_float_unused (* Was: all fields are floats. Now: unused *)
   | Record_unboxed of bool (* Unboxed single-field record, inlined or not *)
   | Record_inlined of
       (* Inlined record *)
diff --git a/docs/docson/build-schema.json b/docs/docson/build-schema.json
index 2c3e1b30fec..9fe363ce4a5 100644
--- a/docs/docson/build-schema.json
+++ b/docs/docson/build-schema.json
@@ -446,7 +446,7 @@
       "properties": {
         "number": {
           "type": "string",
-          "description": "Default: \"+a-4-9-20-41-50-102\". Go [here](https://rescript-lang.org/docs/manual/latest/warning-numbers) for the meanings of the warning flags"
+          "description": "Default: \"+a-4-9-20-41-102\". Go [here](https://rescript-lang.org/docs/manual/latest/warning-numbers) for the meanings of the warning flags"
         },
         "error": {
           "oneOf": [
diff --git a/packages/dev-playground/src/CompilerApi.res b/packages/dev-playground/src/CompilerApi.res
index 361204c69e6..1715921e14d 100644
--- a/packages/dev-playground/src/CompilerApi.res
+++ b/packages/dev-playground/src/CompilerApi.res
@@ -89,7 +89,7 @@ type normalizedConfig = {
   sourceMapRoot: string,
 }
 
-let defaultWarnFlags = "+a-4-9-20-40-41-42-50-61-102-109"
+let defaultWarnFlags = "+a-4-9-20-41-102-109"
 
 let defaultCompilerVersion = Env.viteDefaultCompilerVersion->Option.getOr("local")
 
diff --git a/tests/ERROR_VARIANTS.md b/tests/ERROR_VARIANTS.md
index 4449cd3a240..e0e3e7e3efc 100644
--- a/tests/ERROR_VARIANTS.md
+++ b/tests/ERROR_VARIANTS.md
@@ -551,9 +551,9 @@ PPX/malformed ASTs, or test helper APIs, were retained and reclassified.
 ## Warnings
 
 Warnings are declared in [`compiler/ext/warnings.ml`](../compiler/ext/warnings.ml).
-The default warning set is `+a-4-9-20-41-50-102`
+The default warning set is `+a-4-9-20-41-102`
 ([`compiler/ext/bsc_warnings.ml`](../compiler/ext/bsc_warnings.ml)), so
-warnings 4, 9, 20, 41, 50, and 102 are disabled by default; the rest are
+warnings 4, 9, 20, 41, and 102 are disabled by default; the rest are
 enabled. Fixtures use `-w +A` (everything on) so default-disabled
 warnings still fire.