diff --git a/src/main/java/org/apache/commons/collections4/bag/PredicatedBag.java b/src/main/java/org/apache/commons/collections4/bag/PredicatedBag.java
index e5857f396..44796d73c 100644
--- a/src/main/java/org/apache/commons/collections4/bag/PredicatedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/PredicatedBag.java
@@ -55,6 +55,7 @@ public class PredicatedBag<E> extends PredicatedCollection<E> implements Bag<E>
      * @return a new predicated Bag
      * @throws IllegalArgumentException if bag or predicate is null
      * @throws IllegalArgumentException if the bag contains invalid elements
+     * @since 4.0
      */
     public static <E> PredicatedBag<E> predicatedBag(final Bag<E> bag, final Predicate<? super E> predicate) {
         return new PredicatedBag<E>(bag, predicate);
diff --git a/src/main/java/org/apache/commons/collections4/bag/PredicatedSortedBag.java b/src/main/java/org/apache/commons/collections4/bag/PredicatedSortedBag.java
index a3312c798..005e6aed7 100644
--- a/src/main/java/org/apache/commons/collections4/bag/PredicatedSortedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/PredicatedSortedBag.java
@@ -54,6 +54,7 @@ public class PredicatedSortedBag<E> extends PredicatedBag<E> implements SortedBa
      * @return a new predicated SortedBag
      * @throws IllegalArgumentException if bag or predicate is null
      * @throws IllegalArgumentException if the bag contains invalid elements
+     * @since 4.0
      */
     public static <E> PredicatedSortedBag<E> predicatedSortedBag(final SortedBag<E> bag,
                                                                  final Predicate<? super E> predicate) {
diff --git a/src/main/java/org/apache/commons/collections4/bag/SynchronizedBag.java b/src/main/java/org/apache/commons/collections4/bag/SynchronizedBag.java
index 5ae55e147..6c3e0bc75 100644
--- a/src/main/java/org/apache/commons/collections4/bag/SynchronizedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/SynchronizedBag.java
@@ -45,6 +45,7 @@ public class SynchronizedBag<E> extends SynchronizedCollection<E> implements Bag
      * @param bag  the bag to decorate, must not be null
      * @return a new synchronized Bag
      * @throws IllegalArgumentException if bag is null
+     * @since 4.0
      */
     public static <E> SynchronizedBag<E> synchronizedBag(final Bag<E> bag) {
         return new SynchronizedBag<E>(bag);
diff --git a/src/main/java/org/apache/commons/collections4/bag/SynchronizedSortedBag.java b/src/main/java/org/apache/commons/collections4/bag/SynchronizedSortedBag.java
index 609319a2f..3b24a654a 100644
--- a/src/main/java/org/apache/commons/collections4/bag/SynchronizedSortedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/SynchronizedSortedBag.java
@@ -45,6 +45,7 @@ public class SynchronizedSortedBag<E> extends SynchronizedBag<E> implements Sort
      * @param bag  the bag to decorate, must not be null
      * @return a new synchronized SortedBag
      * @throws IllegalArgumentException if bag is null
+     * @since 4.0
      */
     public static <E> SynchronizedSortedBag<E> synchronizedSortedBag(final SortedBag<E> bag) {
         return new SynchronizedSortedBag<E>(bag);
diff --git a/src/main/java/org/apache/commons/collections4/bag/TransformedBag.java b/src/main/java/org/apache/commons/collections4/bag/TransformedBag.java
index 7864619ca..c75ddc5f4 100644
--- a/src/main/java/org/apache/commons/collections4/bag/TransformedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/TransformedBag.java
@@ -52,6 +52,7 @@ public class TransformedBag<E> extends TransformedCollection<E> implements Bag<E
      * @param transformer  the transformer to use for conversion, must not be null
      * @return a new transformed Bag
      * @throws IllegalArgumentException if bag or transformer is null
+     * @since 4.0
      */
     public static <E> Bag<E> transformingBag(final Bag<E> bag, final Transformer<? super E, ? extends E> transformer) {
         return new TransformedBag<E>(bag, transformer);
diff --git a/src/main/java/org/apache/commons/collections4/bag/TransformedSortedBag.java b/src/main/java/org/apache/commons/collections4/bag/TransformedSortedBag.java
index 8bc8d1c3e..962ce31ab 100644
--- a/src/main/java/org/apache/commons/collections4/bag/TransformedSortedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/TransformedSortedBag.java
@@ -50,6 +50,7 @@ public class TransformedSortedBag<E> extends TransformedBag<E> implements Sorted
      * @param transformer  the transformer to use for conversion, must not be null
      * @return a new transformed SortedBag
      * @throws IllegalArgumentException if bag or transformer is null
+     * @since 4.0
      */
     public static <E> TransformedSortedBag<E> transformingSortedBag(final SortedBag<E> bag,
             final Transformer<? super E, ? extends E> transformer) {
diff --git a/src/main/java/org/apache/commons/collections4/bag/UnmodifiableBag.java b/src/main/java/org/apache/commons/collections4/bag/UnmodifiableBag.java
index 50e9ec860..f4f0bdc0b 100644
--- a/src/main/java/org/apache/commons/collections4/bag/UnmodifiableBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/UnmodifiableBag.java
@@ -54,6 +54,7 @@ public final class UnmodifiableBag<E>
      * @param bag  the bag to decorate, must not be null
      * @return an unmodifiable Bag
      * @throws IllegalArgumentException if bag is null
+     * @since 4.0
      */
     public static <E> Bag<E> unmodifiableBag(final Bag<E> bag) {
         if (bag instanceof Unmodifiable) {
diff --git a/src/main/java/org/apache/commons/collections4/bag/UnmodifiableSortedBag.java b/src/main/java/org/apache/commons/collections4/bag/UnmodifiableSortedBag.java
index d702c38fc..99ca360c4 100644
--- a/src/main/java/org/apache/commons/collections4/bag/UnmodifiableSortedBag.java
+++ b/src/main/java/org/apache/commons/collections4/bag/UnmodifiableSortedBag.java
@@ -54,6 +54,7 @@ public final class UnmodifiableSortedBag<E>
      * @param bag  the bag to decorate, must not be null
      * @return an unmodifiable SortedBag
      * @throws IllegalArgumentException if bag is null
+     * @since 4.0
      */
     public static <E> SortedBag<E> unmodifiableSortedBag(final SortedBag<E> bag) {
         if (bag instanceof Unmodifiable) {