diff --git a/phpunitpolyfills-autoload.php b/phpunitpolyfills-autoload.php
index 1a59b73..265bb61 100644
--- a/phpunitpolyfills-autoload.php
+++ b/phpunitpolyfills-autoload.php
@@ -10,12 +10,16 @@
 
 	/**
 	 * Custom autoloader.
+	 *
+	 * @since 0.1.0
 	 */
 	final class Autoload {
 
 		/**
 		 * Version number.
 		 *
+		 * @since 1.0.1
+		 *
 		 * @var string
 		 */
 		const VERSION = '3.0.0';
diff --git a/src/Exceptions/InvalidComparisonMethodException.php b/src/Exceptions/InvalidComparisonMethodException.php
index a3d077a..089f07b 100644
--- a/src/Exceptions/InvalidComparisonMethodException.php
+++ b/src/Exceptions/InvalidComparisonMethodException.php
@@ -9,6 +9,8 @@
  *
  * PHPUnit natively throws a range of different exceptions.
  * The polyfills throw just one exception type with different messages.
+ *
+ * @since 1.0.0
  */
 final class InvalidComparisonMethodException extends Exception {
 
diff --git a/src/Helpers/ComparatorValidator.php b/src/Helpers/ComparatorValidator.php
index 5329511..0de5dd3 100644
--- a/src/Helpers/ComparatorValidator.php
+++ b/src/Helpers/ComparatorValidator.php
@@ -19,6 +19,8 @@
  * ---------------------------------------------------------------------------------------------
  *
  * @internal
+ *
+ * @since 3.0.0
  */
 final class ComparatorValidator {
 
diff --git a/src/Helpers/ResourceHelper.php b/src/Helpers/ResourceHelper.php
index 15769fc..020fc51 100644
--- a/src/Helpers/ResourceHelper.php
+++ b/src/Helpers/ResourceHelper.php
@@ -16,6 +16,8 @@
  * ---------------------------------------------------------------------------------------------
  *
  * @internal
+ *
+ * @since 1.0.0
  */
 final class ResourceHelper {
 
diff --git a/src/Polyfills/AssertArrayWithListKeys_Empty.php b/src/Polyfills/AssertArrayWithListKeys_Empty.php
index 0e647c6..a5df522 100644
--- a/src/Polyfills/AssertArrayWithListKeys_Empty.php
+++ b/src/Polyfills/AssertArrayWithListKeys_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 11.0.0 in which the polyfill is not needed.
+ *
+ * @since 3.0.0
  */
 trait AssertArrayWithListKeys {}
diff --git a/src/Polyfills/AssertClosedResource.php b/src/Polyfills/AssertClosedResource.php
index 36f0c5c..f38025c 100644
--- a/src/Polyfills/AssertClosedResource.php
+++ b/src/Polyfills/AssertClosedResource.php
@@ -14,6 +14,8 @@
  *
  * @link https://github.com/sebastianbergmann/phpunit/issues/4276
  * @link https://github.com/sebastianbergmann/phpunit/pull/4365
+ *
+ * @since 1.0.0
  */
 trait AssertClosedResource {
 
diff --git a/src/Polyfills/AssertClosedResource_Empty.php b/src/Polyfills/AssertClosedResource_Empty.php
index 8cb4c55..863963c 100644
--- a/src/Polyfills/AssertClosedResource_Empty.php
+++ b/src/Polyfills/AssertClosedResource_Empty.php
@@ -10,6 +10,8 @@
  * For consistency, the "should this test be skipped" method is included
  * as the PHPUnit native versions of the `assertIs[Not]ClosedResource()`
  * assertions are affected by the same bugs.
+ *
+ * @since 1.0.0
  */
 trait AssertClosedResource {
 
diff --git a/src/Polyfills/AssertEqualsSpecializations.php b/src/Polyfills/AssertEqualsSpecializations.php
index ac04cef..c37b89d 100644
--- a/src/Polyfills/AssertEqualsSpecializations.php
+++ b/src/Polyfills/AssertEqualsSpecializations.php
@@ -12,6 +12,8 @@
  * deprecated in PHPUnit 7.5.0 and removed in PHPUnit 9.0.0.
  *
  * @link https://github.com/sebastianbergmann/phpunit/issues/3340
+ *
+ * @since 0.1.0
  */
 trait AssertEqualsSpecializations {
 
diff --git a/src/Polyfills/AssertEqualsSpecializations_Empty.php b/src/Polyfills/AssertEqualsSpecializations_Empty.php
index b8fbaa6..ef848bb 100644
--- a/src/Polyfills/AssertEqualsSpecializations_Empty.php
+++ b/src/Polyfills/AssertEqualsSpecializations_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 7.5.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait AssertEqualsSpecializations {}
diff --git a/src/Polyfills/AssertFileEqualsSpecializations.php b/src/Polyfills/AssertFileEqualsSpecializations.php
index 1ddbbca..c108e6d 100644
--- a/src/Polyfills/AssertFileEqualsSpecializations.php
+++ b/src/Polyfills/AssertFileEqualsSpecializations.php
@@ -15,6 +15,8 @@
  *
  * @link https://github.com/sebastianbergmann/phpunit/issues/3949
  * @link https://github.com/sebastianbergmann/phpunit/issues/3951
+ *
+ * @since 0.1.0
  */
 trait AssertFileEqualsSpecializations {
 
diff --git a/src/Polyfills/AssertFileEqualsSpecializations_Empty.php b/src/Polyfills/AssertFileEqualsSpecializations_Empty.php
index 18009a8..56adb71 100644
--- a/src/Polyfills/AssertFileEqualsSpecializations_Empty.php
+++ b/src/Polyfills/AssertFileEqualsSpecializations_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 8.5.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait AssertFileEqualsSpecializations {}
diff --git a/src/Polyfills/AssertIsType.php b/src/Polyfills/AssertIsType.php
index 34007d6..487d654 100644
--- a/src/Polyfills/AssertIsType.php
+++ b/src/Polyfills/AssertIsType.php
@@ -14,6 +14,8 @@
  *
  * @link https://github.com/sebastianbergmann/phpunit/issues/3368
  * @link https://github.com/sebastianbergmann/phpunit/issues/3369
+ *
+ * @since 0.1.0
  */
 trait AssertIsType {
 
diff --git a/src/Polyfills/AssertIsType_Empty.php b/src/Polyfills/AssertIsType_Empty.php
index e89add2..14b7bfd 100644
--- a/src/Polyfills/AssertIsType_Empty.php
+++ b/src/Polyfills/AssertIsType_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 7.5.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait AssertIsType {}
diff --git a/src/Polyfills/AssertObjectEquals.php b/src/Polyfills/AssertObjectEquals.php
index efd13e7..d814d1a 100644
--- a/src/Polyfills/AssertObjectEquals.php
+++ b/src/Polyfills/AssertObjectEquals.php
@@ -18,6 +18,8 @@
  * @link https://github.com/sebastianbergmann/phpunit/issues/4707
  * @link https://github.com/sebastianbergmann/phpunit/commit/1dba8c3a4b2dd04a3ff1869f75daaeb6757a14ee
  * @link https://github.com/sebastianbergmann/phpunit/commit/6099c5eefccfda860c889f575d58b5fe6cc10c83
+ *
+ * @since 1.0.0
  */
 trait AssertObjectEquals {
 
diff --git a/src/Polyfills/AssertObjectEquals_Empty.php b/src/Polyfills/AssertObjectEquals_Empty.php
index 4390a97..9546154 100644
--- a/src/Polyfills/AssertObjectEquals_Empty.php
+++ b/src/Polyfills/AssertObjectEquals_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 9.4.0 in which this polyfill is not needed.
+ *
+ * @since 1.0.0
  */
 trait AssertObjectEquals {}
diff --git a/src/Polyfills/AssertObjectNotEquals.php b/src/Polyfills/AssertObjectNotEquals.php
index 8463cb2..2f9c0bd 100644
--- a/src/Polyfills/AssertObjectNotEquals.php
+++ b/src/Polyfills/AssertObjectNotEquals.php
@@ -16,6 +16,8 @@
  *
  * @link https://github.com/sebastianbergmann/phpunit/issues/5811
  * @link https://github.com/sebastianbergmann/phpunit/commit/8e3b7c18506312df0676f2e079c414cc56b49f69
+ *
+ * @since 3.0.0
  */
 trait AssertObjectNotEquals {
 
diff --git a/src/Polyfills/AssertObjectNotEquals_Empty.php b/src/Polyfills/AssertObjectNotEquals_Empty.php
index 7d345df..4f92f67 100644
--- a/src/Polyfills/AssertObjectNotEquals_Empty.php
+++ b/src/Polyfills/AssertObjectNotEquals_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 11.2.0 in which this polyfill is not needed.
+ *
+ * @since 3.0.0
  */
 trait AssertObjectNotEquals {}
diff --git a/src/Polyfills/AssertObjectProperty.php b/src/Polyfills/AssertObjectProperty.php
index 5e5a06e..1b98bf9 100644
--- a/src/Polyfills/AssertObjectProperty.php
+++ b/src/Polyfills/AssertObjectProperty.php
@@ -18,6 +18,8 @@
  *
  * @link https://github.com/sebastianbergmann/phpunit/pull/5231
  * @link https://github.com/sebastianbergmann/phpunit/issues/5478
+ *
+ * @since 2.0.0
  */
 trait AssertObjectProperty {
 
diff --git a/src/Polyfills/AssertObjectProperty_Empty.php b/src/Polyfills/AssertObjectProperty_Empty.php
index fd7e73e..8cb93ac 100644
--- a/src/Polyfills/AssertObjectProperty_Empty.php
+++ b/src/Polyfills/AssertObjectProperty_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 9.6.11 < 10.0.0 and PHPUnit >= 10.1.0 in which this polyfill is not needed.
+ *
+ * @since 2.0.0
  */
 trait AssertObjectProperty {}
diff --git a/src/Polyfills/AssertStringContains.php b/src/Polyfills/AssertStringContains.php
index 151e4ad..980e386 100644
--- a/src/Polyfills/AssertStringContains.php
+++ b/src/Polyfills/AssertStringContains.php
@@ -13,6 +13,8 @@
  * @link https://github.com/sebastianbergmann/phpunit/issues/3422
  * @link https://github.com/sebastianbergmann/phpunit/issues/2520
  * @link https://github.com/sebastianbergmann/phpunit/pull/2778
+ *
+ * @since 0.1.0
  */
 trait AssertStringContains {
 
diff --git a/src/Polyfills/AssertStringContains_Empty.php b/src/Polyfills/AssertStringContains_Empty.php
index 6d82e87..1002b00 100644
--- a/src/Polyfills/AssertStringContains_Empty.php
+++ b/src/Polyfills/AssertStringContains_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 7.5.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait AssertStringContains {}
diff --git a/src/Polyfills/AssertionRenames.php b/src/Polyfills/AssertionRenames.php
index c30480b..659a6f1 100644
--- a/src/Polyfills/AssertionRenames.php
+++ b/src/Polyfills/AssertionRenames.php
@@ -38,6 +38,8 @@
  * @link https://github.com/sebastianbergmann/phpunit/issues/4088
  * @link https://github.com/sebastianbergmann/phpunit/issues/4089
  * @link https://github.com/sebastianbergmann/phpunit/issues/4090
+ *
+ * @since 0.1.0
  */
 trait AssertionRenames {
 
diff --git a/src/Polyfills/AssertionRenames_Empty.php b/src/Polyfills/AssertionRenames_Empty.php
index 4de7858..250aa5d 100644
--- a/src/Polyfills/AssertionRenames_Empty.php
+++ b/src/Polyfills/AssertionRenames_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 9.1.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait AssertionRenames {}
diff --git a/src/Polyfills/EqualToSpecializations.php b/src/Polyfills/EqualToSpecializations.php
index c896c91..89581e2 100644
--- a/src/Polyfills/EqualToSpecializations.php
+++ b/src/Polyfills/EqualToSpecializations.php
@@ -14,6 +14,8 @@
  * never deprecated but leads to unexpected behaviour as they are ignored in PHPUnit 9.0.0.
  *
  * @link https://github.com/sebastianbergmann/phpunit/commit/43c01a4e0c74a4bf019a8d879bced5146af2fbb6
+ *
+ * @since 1.0.0
  */
 trait EqualToSpecializations {
 
diff --git a/src/Polyfills/EqualToSpecializations_Empty.php b/src/Polyfills/EqualToSpecializations_Empty.php
index a03eb52..6275d07 100644
--- a/src/Polyfills/EqualToSpecializations_Empty.php
+++ b/src/Polyfills/EqualToSpecializations_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 9.0.0 in which this polyfill is not needed.
+ *
+ * @since 1.0.0
  */
 trait EqualToSpecializations {}
diff --git a/src/Polyfills/ExpectExceptionMessageMatches.php b/src/Polyfills/ExpectExceptionMessageMatches.php
index e9267f3..85778dd 100644
--- a/src/Polyfills/ExpectExceptionMessageMatches.php
+++ b/src/Polyfills/ExpectExceptionMessageMatches.php
@@ -13,6 +13,8 @@
  * @link https://github.com/sebastianbergmann/phpunit/commit/d1199cb2e43a934b51521656be9748f63febe18e
  * @link https://github.com/sebastianbergmann/phpunit/issues/4133
  * @link https://github.com/sebastianbergmann/phpunit/issues/3957
+ *
+ * @since 0.1.0
  */
 trait ExpectExceptionMessageMatches {
 
diff --git a/src/Polyfills/ExpectExceptionMessageMatches_Empty.php b/src/Polyfills/ExpectExceptionMessageMatches_Empty.php
index f6278c1..7ddc36f 100644
--- a/src/Polyfills/ExpectExceptionMessageMatches_Empty.php
+++ b/src/Polyfills/ExpectExceptionMessageMatches_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 8.4.0 in which this polyfill is not needed.
+ *
+ * @since 0.1.0
  */
 trait ExpectExceptionMessageMatches {}
diff --git a/src/Polyfills/ExpectUserDeprecation.php b/src/Polyfills/ExpectUserDeprecation.php
index e0069f4..5a48620 100644
--- a/src/Polyfills/ExpectUserDeprecation.php
+++ b/src/Polyfills/ExpectUserDeprecation.php
@@ -13,6 +13,8 @@
  * Note: PHPUnit 10 is not and will not be supported for these polyfills.
  *
  * @link https://github.com/sebastianbergmann/phpunit/pull/5605
+ *
+ * @since 3.0.0
  */
 trait ExpectUserDeprecation {
 
diff --git a/src/Polyfills/ExpectUserDeprecation_Empty.php b/src/Polyfills/ExpectUserDeprecation_Empty.php
index 7a1ac9b..249df88 100644
--- a/src/Polyfills/ExpectUserDeprecation_Empty.php
+++ b/src/Polyfills/ExpectUserDeprecation_Empty.php
@@ -4,5 +4,7 @@
 
 /**
  * Empty trait for use with PHPUnit >= 11.0.0 in which this polyfill is not needed.
+ *
+ * @since 3.0.0
  */
 trait ExpectUserDeprecation {}
diff --git a/src/TestCases/TestCasePHPUnitGte8.php b/src/TestCases/TestCasePHPUnitGte8.php
index 8828011..3b9bde0 100644
--- a/src/TestCases/TestCasePHPUnitGte8.php
+++ b/src/TestCases/TestCasePHPUnitGte8.php
@@ -24,6 +24,8 @@
  * methods to get round the signature change in PHPUnit 8.
  *
  * When using this TestCase, the snakecase method names need to be used to overload a fixture method.
+ *
+ * @since 0.1.0
  */
 abstract class TestCase extends PHPUnit_TestCase {
 
@@ -69,6 +71,8 @@ protected function setUp(): void {
 	 *
 	 * This method is called before the execution of a test starts and after setUp() is called.
 	 *
+	 * @since 0.2.0
+	 *
 	 * @return void
 	 */
 	protected function assertPreConditions(): void {
@@ -81,6 +85,8 @@ protected function assertPreConditions(): void {
 	 *
 	 * This method is called before the execution of a test ends and before tearDown() is called.
 	 *
+	 * @since 0.2.0
+	 *
 	 * @return void
 	 */
 	protected function assertPostConditions(): void {
diff --git a/src/TestCases/TestCasePHPUnitLte7.php b/src/TestCases/TestCasePHPUnitLte7.php
index 6245003..078a748 100644
--- a/src/TestCases/TestCasePHPUnitLte7.php
+++ b/src/TestCases/TestCasePHPUnitLte7.php
@@ -27,6 +27,8 @@
  * methods to get round the signature change in PHPUnit 8.
  *
  * When using this TestCase, the snakecase method names need to be used to overload a fixture method.
+ *
+ * @since 0.1.0
  */
 abstract class TestCase extends PHPUnit_TestCase {
 
@@ -75,6 +77,8 @@ protected function setUp() {
 	 *
 	 * This method is called before the execution of a test starts and after setUp() is called.
 	 *
+	 * @since 0.2.0
+	 *
 	 * @return void
 	 */
 	protected function assertPreConditions() {
@@ -87,6 +91,8 @@ protected function assertPreConditions() {
 	 *
 	 * This method is called before the execution of a test ends and before tearDown() is called.
 	 *
+	 * @since 0.2.0
+	 *
 	 * @return void
 	 */
 	protected function assertPostConditions() {
diff --git a/src/TestCases/XTestCase.php b/src/TestCases/XTestCase.php
index 9041f46..f9762e7 100644
--- a/src/TestCases/XTestCase.php
+++ b/src/TestCases/XTestCase.php
@@ -33,6 +33,8 @@
  * `@after` and `@afterClass` annotations.
  * The naming of the overloaded methods is open as long as the method names don't conflict with
  * the PHPUnit native method names.
+ *
+ * @since 0.1.0
  */
 abstract class XTestCase extends PHPUnit_TestCase {
 
diff --git a/src/TestListeners/TestListenerDefaultImplementationPHPUnit6.php b/src/TestListeners/TestListenerDefaultImplementationPHPUnit6.php
index 93e1d97..d6bca59 100644
--- a/src/TestListeners/TestListenerDefaultImplementationPHPUnit6.php
+++ b/src/TestListeners/TestListenerDefaultImplementationPHPUnit6.php
@@ -16,6 +16,8 @@
  *
  * When using this TestListener trait, the snake_case method names need to be used to implement
  * the listener functionality.
+ *
+ * @since 0.2.0
  */
 trait TestListenerDefaultImplementation {
 
diff --git a/src/TestListeners/TestListenerDefaultImplementationPHPUnitGte7.php b/src/TestListeners/TestListenerDefaultImplementationPHPUnitGte7.php
index ed6d61c..1a17523 100644
--- a/src/TestListeners/TestListenerDefaultImplementationPHPUnitGte7.php
+++ b/src/TestListeners/TestListenerDefaultImplementationPHPUnitGte7.php
@@ -16,6 +16,8 @@
  *
  * When using this TestListener trait, the snake_case method names need to be used to implement
  * the listener functionality.
+ *
+ * @since 0.2.0
  */
 trait TestListenerDefaultImplementation {
 
diff --git a/src/TestListeners/TestListenerSnakeCaseMethods.php b/src/TestListeners/TestListenerSnakeCaseMethods.php
index 4d6a08f..1072f48 100644
--- a/src/TestListeners/TestListenerSnakeCaseMethods.php
+++ b/src/TestListeners/TestListenerSnakeCaseMethods.php
@@ -12,6 +12,8 @@
 /**
  * Renamed snake_case TestListener method collection used by the TestListenerDefaultImplementation traits.
  *
+ * @since 0.2.0
+ *
  * @phpcs:disable VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- This is intentional as these are template methods.
  */
 trait TestListenerSnakeCaseMethods {