diff --git a/src/wp-includes/class-wp-object-cache.php b/src/wp-includes/class-wp-object-cache.php
index cd84b17753..8136ea3ad9 100644
--- a/src/wp-includes/class-wp-object-cache.php
+++ b/src/wp-includes/class-wp-object-cache.php
@@ -156,7 +156,7 @@ class WP_Object_Cache {
 		$message = is_string( $key )
 			? __( 'Cache key must not be an empty string.' )
 			/* translators: %s: The type of the given cache key. */
-			: sprintf( __( 'Cache key must be integer or non-empty string, %s given.' ), $type );
+			: sprintf( __( 'Cache key must be an integer or a non-empty string, %s given.' ), $type );
 
 		_doing_it_wrong(
 			sprintf( '%s::%s', __CLASS__, debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, 2 )[1]['function'] ),
diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index e3e281b1d6..2112323704 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -7034,24 +7034,28 @@ function _get_non_cached_ids( $object_ids, $cache_key ) {
 }
 
 /**
- * Checks whether the given cache ID is either an integer or iterger-like strings.
- * Both `16` and `"16"` are considered valid, other numeric types and numeric
- * strings (`16.3` and `"16.3"`) are considered invalid.
+ * Checks whether the given cache ID is either an integer or an integer-like string.
+ *
+ * Both `16` and `"16"` are considered valid, other numeric types and numeric strings
+ * (`16.3` and `"16.3"`) are considered invalid.
  *
  * @since 6.3.0
  *
- * @param mixed $object_id The cache id to validate.
- * @return bool Whether the given $object_id is a valid cache id.
+ * @param mixed $object_id The cache ID to validate.
+ * @return bool Whether the given $object_id is a valid cache ID.
  */
 function _validate_cache_id( $object_id ) {
-	// Unfortunately filter_var() is considered an optional extension
+	/*
+	 * filter_var() could be used here, but the `filter` PHP extension
+	 * is considered optional and may not be available.
+	 */
 	if ( is_int( $object_id )
 		|| ( is_string( $object_id ) && (string) (int) $object_id === $object_id ) ) {
 		return true;
 	}
 
-	/* translators: %s: The type of the given object id. */
-	$message = sprintf( __( 'Object id must be integer, %s given.' ), gettype( $object_id ) );
+	/* translators: %s: The type of the given object ID. */
+	$message = sprintf( __( 'Object ID must be an integer, %s given.' ), gettype( $object_id ) );
 	_doing_it_wrong( '_get_non_cached_ids', $message, '6.3.0' );
 
 	return false;
diff --git a/tests/phpunit/tests/functions/getNonCachedIds.php b/tests/phpunit/tests/functions/getNonCachedIds.php
index 300477d8ad..d8df0e11a6 100644
--- a/tests/phpunit/tests/functions/getNonCachedIds.php
+++ b/tests/phpunit/tests/functions/getNonCachedIds.php
@@ -7,6 +7,7 @@
  * @group cache
  *
  * @covers ::_get_non_cached_ids
+ * @covers ::_validate_cache_id
  */
 class Tests_Functions_GetNonCachedIds extends WP_UnitTestCase {
 
@@ -28,7 +29,7 @@ class Tests_Functions_GetNonCachedIds extends WP_UnitTestCase {
 	 *
 	 * @dataProvider data_valid_ids_should_be_returned_as_integers
 	 *
-	 * @param mixed $object_id The object id.
+	 * @param mixed $object_id The object ID.
 	 */
 	public function test_valid_ids_should_be_returned_as_integers( $object_id ) {
 		$this->assertSame(
@@ -69,7 +70,7 @@ class Tests_Functions_GetNonCachedIds extends WP_UnitTestCase {
 	 *
 	 * @dataProvider data_invalid_cache_ids_should_throw_a_notice
 	 *
-	 * @param mixed $object_id The object id.
+	 * @param mixed $object_id The object ID.
 	 */
 	public function test_invalid_cache_ids_should_throw_a_notice( $object_id ) {
 		$this->setExpectedIncorrectUsage( '_get_non_cached_ids' );