[Serializer] Update the getSupportedTypes() docs of custom serializers

serializer/custom_normalizer.rst

@@ -164,31 +164,29 @@ Improving Performance of Normalizers/Denormalizers
 
     The ``getSupportedTypes()`` method was introduced in Symfony 6.3.
 
-Both :class:`Symfony\\Component\\Serializer\\Normalizer\\NormalizerInterface`
-and :class:`Symfony\\Component\\Serializer\\Normalizer\\DenormalizerInterface`
-contain a new method ``getSupportedTypes()``. This method allows normalizers or
-denormalizers to declare the type of objects they can handle, and whether they
-are cacheable. With this info, even if the ``supports*()`` call is not cacheable,
-the Serializer can skip a ton of method calls to ``supports*()`` improving
-performance substantially in some cases.
+Both :class:Symfony\\Component\\Serializer\\Normalizer\\NormalizerInterface
+and :class:Symfony\\Component\\Serializer\\Normalizer\\DenormalizerInterface
+define a ``getSupportedTypes()`` method to declare which types they support and
+whether their ``supports*()`` result can be cached.
+
+This **does not** cache the actual normalization or denormalization result. It
+only **caches the decision** of whether a normalizer supports a given type, allowing
+the Serializer to skip unnecessary ``supports*()`` calls and improve performance.
 
 The ``getSupportedTypes()`` method should return an array where the keys
-represent the supported types, and the values indicate whether the result of
-the ``supports*()`` method call can be cached or not. The format of the
-returned array is as follows:
+represent the supported types, and the values indicate whether the result of the
+corresponding ``supports*()`` call can be cached. The array format is as follows:
 
 #. The special key ``object`` can be used to indicate that the normalizer or
    denormalizer supports any classes or interfaces.
 #. The special key ``*`` can be used to indicate that the normalizer or
-   denormalizer might support any types.
-#. The other keys in the array should correspond to specific types that the
-   normalizer or denormalizer supports.
-#. The values associated with each type should be a boolean indicating if the
-   result of the ``supports*()`` method call for that type can be cached or not.
-   A value of ``true`` means that the result is cacheable, while ``false`` means
-   that the result is not cacheable.
-#. A ``null`` value for a type means that the normalizer or denormalizer does
-   not support that type.
+   denormalizer might support any type.
+#. Other keys should correspond to specific types that the normalizer or
+   denormalizer supports.
+#. The values should be booleans indicating whether the result of the
+   ``supports*()`` call for that type is cacheable. Use ``true`` if the result
+   can be cached, ``false`` if it cannot.
+#. A ``null`` value means the normalizer or denormalizer does not support that type.
 
 Here is an example of how to use the ``getSupportedTypes()`` method::
 
@@ -201,9 +199,9 @@ Here is an example of how to use the ``getSupportedTypes()`` method::
         public function getSupportedTypes(?string $format): array
         {
             return [
-                'object' => null,             // Doesn't support any classes or interfaces
-                '*' => false,                 // Supports any other types, but the result is not cacheable
-                MyCustomClass::class => true, // Supports MyCustomClass and result is cacheable
+                'object' => null,             // doesn't support any classes or interfaces
+                '*' => false,                 // supports any other types, but the decision is not cacheable
+                MyCustomClass::class => true, // supports MyCustomClass and decision is cacheable
             ];
         }
     }