diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 243ca1226..567fe8aeb 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -1,5 +1,18 @@
 = Changelog
 
+== 2.2
+
+- Improving comments presentation
+- Add `CCOpt.return_if`
+- Add `CCOpt.flatten`
+- Add `CCString.{,r}drop_while`
+- add many missing functions to `CCListLabels`
+- test: consistency `CCList{,Labels}`
+
+- fix(arrayLabels): compatibility with 4.07
+- fix: compatibility for CCArrayLabels
+- test: add compatibility checks between `CCArray{,Labels}`
+
 == 2.1
 
 - make `CCInt64` compatible with `Int64` (breaking!) (closes #192)
diff --git a/README.adoc b/README.adoc
index 9050155fd..a0fc756da 100644
--- a/README.adoc
+++ b/README.adoc
@@ -560,8 +560,6 @@ can be removed.
    removed deprecated functions, etc.
 . update `CHANGELOG.adoc` (see its end to find the right git command)
 . commit the changes
-. `git checkout stable`
-. `git merge master`
 . `make test doc`
 . tag, and push both to github
 . `opam pin add containers https://github.com/c-cube/ocaml-containers.git#<release>`
diff --git a/containers.opam b/containers.opam
index ded5b0ed7..6372693d6 100644
--- a/containers.opam
+++ b/containers.opam
@@ -1,6 +1,6 @@
 opam-version: "1.2"
 name: "containers"
-version: "2.1"
+version: "2.2"
 author: "Simon Cruanes"
 maintainer: "simon.cruanes.2007@m4x.org"
 build: [
diff --git a/src/core/CCListLabels.mli b/src/core/CCListLabels.mli
index f0459b61d..efec8391b 100644
--- a/src/core/CCListLabels.mli
+++ b/src/core/CCListLabels.mli
@@ -66,7 +66,7 @@ val fold_map : f:('acc -> 'a -> 'acc * 'b) -> init:'acc -> 'a list -> 'acc * 'b
     @since 0.14 *)
 
 val scan_left : f:('acc -> 'a -> 'acc) -> init:'acc -> 'a list -> 'acc list
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val fold_map2 : f:('acc -> 'a -> 'b -> 'acc * 'c) -> init:'acc -> 'a list -> 'b list -> 'acc * 'c list
 (** [fold_map2] is to [fold_map] what [List.map2] is to [List.map].
@@ -84,7 +84,7 @@ val fold_flat_map : f:('acc -> 'a -> 'acc * 'b list) -> init:'acc -> 'a list ->
     @since 0.14 *)
 
 val count : f:('a -> bool) -> 'a list -> int
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val init : int -> f:(int -> 'a) -> 'a t
 (** [init len ~f] is [f 0; f 1; ...; f (len-1)].
@@ -92,21 +92,21 @@ val init : int -> f:(int -> 'a) -> 'a t
     @since 0.6 *)
 
 val combine : 'a list -> 'b list -> ('a * 'b) list
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val combine_gen : 'a list -> 'b list -> ('a * 'b) gen
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val split : ('a * 'b) t -> 'a t * 'b t
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
 
 val compare_lengths : 'a t -> 'b t -> int
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val compare_length_with : 'a t -> int -> int
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
 
@@ -123,10 +123,10 @@ val fold_product : f:('c -> 'a -> 'b -> 'c) -> init:'c -> 'a t -> 'b t -> 'c
 (** Fold on the cartesian product. *)
 
 val cartesian_product : 'a t t -> 'a t t
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val map_product_l : f:('a -> 'b list) -> 'a list -> 'b list list
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 val diagonal : 'a t -> ('a * 'a) t
 (** All pairs of distinct positions of the list. [list_diagonal l] will
     return the list of [List.nth i l, List.nth j l] if [i < j]. *)
@@ -155,12 +155,12 @@ val sublists_of_len :
 
 val intersperse : x:'a -> 'a list -> 'a list
 (** Insert the first argument between every element of the list.
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 val interleave : 'a list -> 'a list -> 'a list
 (** [interleave [x1…xn] [y1…ym]] is [x1,y1,x2,y2,…] and finishes with
     the suffix of the longest list.
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 val pure : 'a -> 'a t
 (** [pure] is [return]. *)
@@ -201,7 +201,7 @@ val drop_while : f:('a -> bool) -> 'a t -> 'a t
     @since 0.13 *)
 
 val take_drop_while : f:('a -> bool) -> 'a t -> 'a t * 'a t
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val last : int -> 'a t -> 'a t
 (** [last n l] takes the last [n] elements of [l] (or less if
@@ -225,7 +225,7 @@ val find_pred : f:('a -> bool) -> 'a t -> 'a option
     @since 0.11 *)
 
 val find_opt : f:('a -> bool) -> 'a t -> 'a option
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val find_pred_exn : f:('a -> bool) -> 'a t -> 'a
 (** Unsafe version of {!find_pred}.
@@ -257,16 +257,16 @@ val filter_map : f:('a -> 'b option) -> 'a t -> 'b t
     Map and remove elements at the same time. *)
 
 val keep_some : 'a option t -> 'a t
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val keep_ok : ('a, _) Result.result t -> 'a t
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val all_some : 'a option t -> 'a t option
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val all_ok : ('a, 'err) Result.result t -> ('a t, 'err) Result.result
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val sorted_merge : cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
 (** Merges elements from both sorted list. *)
@@ -316,13 +316,13 @@ val iteri : f:(int -> 'a -> unit) -> 'a t -> unit
     itself as second argument. *)
 
 val iteri2 : f:(int -> 'a -> 'b -> unit) -> 'a t -> 'b t -> unit
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val foldi : f:('b -> int -> 'a -> 'b) -> init:'b -> 'a t -> 'b
 (** Like [fold] but it also passes in the index of each element to the folded function. Tail-recursive. *)
 
 val foldi2 : f:('c -> int -> 'a -> 'b -> 'c) -> init:'c -> 'a t -> 'b t -> 'c
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val get_at_idx : int -> 'a t -> 'a option
 (** Get by index in the list.
@@ -330,7 +330,7 @@ val get_at_idx : int -> 'a t -> 'a option
     of the list. *)
 
 val nth_opt : 'a t -> int -> 'a option
-(** @since NEXT_RELEASE *)
+(** @since 2.2 *)
 
 val get_at_idx_exn : int -> 'a t -> 'a
 (** Get the i-th element, or
diff --git a/src/core/CCOpt.mli b/src/core/CCOpt.mli
index 4700cdd14..e6041177e 100644
--- a/src/core/CCOpt.mli
+++ b/src/core/CCOpt.mli
@@ -124,13 +124,13 @@ val choice : 'a t list -> 'a t
 
 val flatten : 'a t t -> 'a t
 (** [flatten] transforms [Some x] into [x].
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 val return_if : bool -> 'a -> 'a t
 (** Apply [Some] or [None] depending on a boolean.
     More precisely, [return_if false x] is [None],
     and [return_if true x] is [Some x].
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 (** {2 Infix Operators}
     @since 0.16 *)
diff --git a/src/core/CCString.mli b/src/core/CCString.mli
index e1eabf663..eb4734f21 100644
--- a/src/core/CCString.mli
+++ b/src/core/CCString.mli
@@ -249,12 +249,12 @@ include S with type t := string
 val drop_while : (char -> bool) -> t -> t
 (** [drop_while f s] discards any characters starting from the left,
     up to the first character [c] not satisfying [f c].
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 val rdrop_while : (char -> bool) -> t -> t
 (** [rdrop_while f s] discards any characters starting from the right,
     up to the first character [c] not satisfying [f c].
-    @since NEXT_RELEASE *)
+    @since 2.2 *)
 
 val ltrim : t -> t
 (** Trim space on the left (see {!String.trim} for more details).