diff --git a/core/modules/text/src/Normalizer/TextItemBaseNormalizer.php b/core/modules/text/src/Normalizer/TextItemBaseNormalizer.php
index fb5327f..d8329f3 100644
--- a/core/modules/text/src/Normalizer/TextItemBaseNormalizer.php
+++ b/core/modules/text/src/Normalizer/TextItemBaseNormalizer.php
@@ -64,14 +64,15 @@ public function normalize($field_item, $format = NULL, array $context = []) {
   }
 
   /**
-   * Computes the processed attribute.
+   * Computes the 'processed' property of TextItemBase fields.
    *
-   * The 'processed' field attribute for fields that extend TextItemBase will
-   * not contain cacheability metadata. Therefore this function returns a
-   * FilterProcessResult which can be used to get both the processed text and
+   * The 'processed' property for fields that extend TextItemBase will
+   * not contain cacheability metadata
+   * (see \Drupal\text\TextProcessed::getValue()). Therefore this function
+   * returns a FilterProcessResult which can carry both the processed text and
    * the cacheability metadata. The cacheability metadata can be bubbled up in
    * GET responses that use this normalization so that the responses can be
-   * cacheable.
+   * cached (and invalidated) correctly.
    *
    * @param \Drupal\text\Plugin\Field\FieldType\TextItemBase $field_item
    *   The field item.
@@ -80,6 +81,7 @@ public function normalize($field_item, $format = NULL, array $context = []) {
    *   The filter process result for the text item.
    *
    * @see \Drupal\text\TextProcessed::getValue()
+   * @see \Drupal\text\Plugin\Field\FieldType\TextItemBase::propertyDefinitions()
    */
   protected function computeProcessedAttribute(TextItemBase $field_item) {
     $value = $field_item->getValue();