diff --git a/core/lib/Drupal/Component/Render/FormattableMarkup.php b/core/lib/Drupal/Component/Render/FormattableMarkup.php
index c8b9ae4..d3e4636 100644
--- a/core/lib/Drupal/Component/Render/FormattableMarkup.php
+++ b/core/lib/Drupal/Component/Render/FormattableMarkup.php
@@ -18,7 +18,7 @@
  * When cast to a string, this object replaces variable placeholders in the
  * string with the arguments passed in during construction and escapes the
  * values so they can be safely displayed as HTML. See the documentation of
- * \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for details
+ * \Drupal\Component\Render\FormattableMarkup::replacePlaceholders() for details
  * on the supported placeholders and how to use them securely. Incorrect use of
  * this class can result in security vulnerabilities.
  *
@@ -37,24 +37,24 @@
  *   risk. Examples:
  *   @code
  *     // Insecure (placeholder within "<" and ">"):
- *     $this->placeholderFormat('<@variable>text</@variable>', ['@variable' => $variable]);
+ *     $this->replacePlaceholders('<@variable>text</@variable>', ['@variable' => $variable]);
  *     // Insecure (placeholder within "<" and ">"):
- *     $this->placeholderFormat('<a @variable>link text</a>', ['@variable' => $variable]);
+ *     $this->replacePlaceholders('<a @variable>link text</a>', ['@variable' => $variable]);
  *     // Insecure (placeholder within "<" and ">"):
- *     $this->placeholderFormat('<a title="@variable">link text</a>', ['@variable' => $variable]);
+ *     $this->replacePlaceholders('<a title="@variable">link text</a>', ['@variable' => $variable]);
  *   @endcode
  *   Only the "href" attribute is supported via the special ":variable"
  *   placeholder, to allow simple links to be inserted:
  *   @code
  *     // Secure (usage of ":variable" placeholder for href attribute):
- *     $this->placeholderFormat('<a href=":variable">link text</a>', [':variable' , $variable]);
+ *     $this->replacePlaceholders('<a href=":variable">link text</a>', [':variable' , $variable]);
  *     // Secure (usage of ":variable" placeholder for href attribute):
- *     $this->placeholderFormat('<a href=":variable" title="static text">link text</a>', [':variable' => $variable]);
+ *     $this->replacePlaceholders('<a href=":variable" title="static text">link text</a>', [':variable' => $variable]);
  *     // Insecure (the "@variable" placeholder does not filter dangerous
  *     // protocols):
- *     $this->placeholderFormat('<a href="@variable">link text</a>', ['@variable' => $variable]);
+ *     $this->replacePlaceholders('<a href="@variable">link text</a>', ['@variable' => $variable]);
  *     // Insecure ("@variable" placeholder within "<" and ">"):
- *     $this->placeholderFormat('<a href=":url" title="@variable">link text</a>', [':url' => $url, '@variable' => $variable]);
+ *     $this->replacePlaceholders('<a href=":url" title="@variable">link text</a>', [':url' => $url, '@variable' => $variable]);
  *   @endcode
  * To build non-minimal HTML, use an HTML template language such as Twig,
  * rather than this class.
@@ -63,7 +63,7 @@
  *
  * @see \Drupal\Core\StringTranslation\TranslatableMarkup
  * @see \Drupal\Core\StringTranslation\PluralTranslatableMarkup
- * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+ * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
  */
 class FormattableMarkup implements MarkupInterface {
 
@@ -79,13 +79,13 @@ class FormattableMarkup implements MarkupInterface {
    *
    * @param string $string
    *   A string containing placeholders. The string itself will not be escaped,
-   *   any unsafe content must be in $args and inserted via placeholders.
+   *   any unsafe content must be in $arguments and inserted via placeholders.
    * @param array $arguments
    *   An array with placeholder replacements, keyed by placeholder. See
-   *   \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for
+   *   \Drupal\Component\Render\FormattableMarkup::replacePlaceholders() for
    *   additional information about placeholders.
    *
-   * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+   * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
    */
   public function __construct($string, array $arguments) {
     $this->string = (string) $string;
@@ -96,7 +96,7 @@ public function __construct($string, array $arguments) {
    * {@inheritdoc}
    */
   public function __toString() {
-    return static::placeholderFormat($this->string, $this->arguments);
+    return static::replacePlaceholders($this->string, $this->arguments);
   }
 
   /**
@@ -124,9 +124,9 @@ public function jsonSerialize() {
    *
    * @param string $string
    *   A string containing placeholders. The string itself is expected to be
-   *   safe and correct HTML. Any unsafe content must be in $args and
+   *   safe and correct HTML. Any unsafe content must be in $arguments and
    *   inserted via placeholders.
-   * @param array $args
+   * @param array $arguments
    *   An associative array of replacements. Each array key should be the same
    *   as a placeholder in $string. The corresponding value should be a string
    *   or an object that implements
@@ -143,7 +143,7 @@ public function jsonSerialize() {
    *       returned string be forcibly sanitized using
    *       \Drupal\Component\Utility\Html::escape().
    *       @code
-   *         $this->placeholderFormat('This will force HTML-escaping of the replacement value: @text', ['@text' => (string) $safe_string_interface_object));
+   *         $this->replacePlaceholders('This will force HTML-escaping of the replacement value: @text', ['@text' => (string) $safe_string_interface_object));
    *       @endcode
    *     Use this placeholder as the default choice for anything displayed on
    *     the site, but not within HTML attributes, JavaScript, or CSS. Doing so
@@ -154,7 +154,7 @@ public function jsonSerialize() {
    *     @code
    *       $string = "%output_text";
    *       $arguments = ['output_text' => 'text output here.'];
-   *       $this->placeholderFormat($string, $arguments);
+   *       $this->replacePlaceholders($string, $arguments);
    *     @endcode
    *     makes the following HTML code:
    *     @code
@@ -169,9 +169,9 @@ public function jsonSerialize() {
    *     wrapped in quotes:
    *     @code
    *     // Secure (with quotes):
-   *     $this->placeholderFormat('<a href=":url">@variable</a>', [':url' => $url, @variable => $variable]);
+   *     $this->replacePlaceholders('<a href=":url">@variable</a>', [':url' => $url, @variable => $variable]);
    *     // Insecure (without quotes):
-   *     $this->placeholderFormat('<a href=:url>@variable</a>', [':url' => $url, @variable => $variable]);
+   *     $this->replacePlaceholders('<a href=:url>@variable</a>', [':url' => $url, @variable => $variable]);
    *     @endcode
    *     When ":variable" comes from arbitrary user input, the result is secure,
    *     but not guaranteed to be a valid URL (which means the resulting output
@@ -191,9 +191,9 @@ public function jsonSerialize() {
    * @see \Drupal\Component\Utility\UrlHelper::stripDangerousProtocols()
    * @see \Drupal\Core\Url::fromUri()
    */
-  protected static function placeholderFormat($string, array $args) {
+  protected static function replacePlaceholders($string, array $arguments) {
     // Transform arguments before inserting them.
-    foreach ($args as $key => $value) {
+    foreach ($arguments as $key => $value) {
       switch ($key[0]) {
         case '@':
           // Escape if the value is not an object from a class that implements
@@ -203,7 +203,7 @@ protected static function placeholderFormat($string, array $args) {
           // return TRUE for content that is safe within HTML fragments, but not
           // within other contexts, so this placeholder type must not be used
           // within HTML attributes, JavaScript, or CSS.
-          $args[$key] = static::placeholderEscape($value);
+          $arguments[$key] = static::placeholderEscape($value);
           break;
 
         case ':':
@@ -219,7 +219,7 @@ protected static function placeholderFormat($string, array $args) {
           // on it prior to passing it in as a placeholder value of this type.
           // @todo Add some advice and stronger warnings.
           //   https://www.drupal.org/node/2569041.
-          $args[$key] = Html::escape($value);
+          $arguments[$key] = Html::escape($value);
           break;
 
         case '%':
@@ -229,12 +229,12 @@ protected static function placeholderFormat($string, array $args) {
           // per the warning above about
           // \Drupal\Component\Utility\SafeMarkup\SafeMarkup::isSafe() and also
           // due to the wrapping markup.
-          $args[$key] = '<em class="placeholder">' . static::placeholderEscape($value) . '</em>';
+          $arguments[$key] = '<em class="placeholder">' . static::placeholderEscape($value) . '</em>';
           break;
       }
     }
 
-    return strtr($string, $args);
+    return strtr($string, $arguments);
   }
 
   /**
diff --git a/core/lib/Drupal/Component/Utility/SafeMarkup.php b/core/lib/Drupal/Component/Utility/SafeMarkup.php
index 8d6387c..83d9bff 100644
--- a/core/lib/Drupal/Component/Utility/SafeMarkup.php
+++ b/core/lib/Drupal/Component/Utility/SafeMarkup.php
@@ -77,14 +77,14 @@ public static function checkPlain($text) {
    *   any unsafe content must be in $args and inserted via placeholders.
    * @param array $args
    *   An array with placeholder replacements, keyed by placeholder. See
-   *   \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for
+   *   \Drupal\Component\Render\FormattableMarkup::replacePlaceholders() for
    *   additional information about placeholders.
    *
    * @return string|\Drupal\Component\Render\MarkupInterface
    *   The formatted string, which is an instance of MarkupInterface unless
    *   sanitization of an unsafe argument was suppressed (see above).
    *
-   * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+   * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
    * @see \Drupal\Component\Render\FormattableMarkup
    *
    * @deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0.
diff --git a/core/lib/Drupal/Core/StringTranslation/PluralTranslatableMarkup.php b/core/lib/Drupal/Core/StringTranslation/PluralTranslatableMarkup.php
index 583ab18..59b4c0d 100644
--- a/core/lib/Drupal/Core/StringTranslation/PluralTranslatableMarkup.php
+++ b/core/lib/Drupal/Core/StringTranslation/PluralTranslatableMarkup.php
@@ -60,7 +60,7 @@ class PluralTranslatableMarkup extends TranslatableMarkup {
    *   "@count new comments".
    * @param array $args
    *   (optional) An array with placeholder replacements, keyed by placeholder.
-   *   See \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for
+   *   See \Drupal\Component\Render\FormattableMarkup::replacePlaceholders() for
    *   additional information about placeholders. Note that you do not need to
    *   include @count in this array; this replacement is done automatically
    *   for the plural cases.
@@ -70,7 +70,7 @@ class PluralTranslatableMarkup extends TranslatableMarkup {
    * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
    *   (optional) The string translation service.
    *
-   * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+   * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
    */
   public function __construct($count, $singular, $plural, array $args = [], array $options = [], TranslationInterface $string_translation = NULL) {
     $this->count = $count;
@@ -127,7 +127,7 @@ public function render() {
     $translated_array = explode(static::DELIMITER, $this->translatedString);
 
     if ($this->count == 1) {
-      return $this->placeholderFormat($translated_array[0], $arguments);
+      return $this->replacePlaceholders($translated_array[0], $arguments);
     }
 
     $index = $this->getPluralIndex();
@@ -148,7 +148,7 @@ public function render() {
       }
     }
 
-    return $this->placeholderFormat($return, $arguments);
+    return $this->replacePlaceholders($return, $arguments);
   }
 
   /**
diff --git a/core/lib/Drupal/Core/StringTranslation/TranslatableMarkup.php b/core/lib/Drupal/Core/StringTranslation/TranslatableMarkup.php
index 8b4902a..8130af8 100644
--- a/core/lib/Drupal/Core/StringTranslation/TranslatableMarkup.php
+++ b/core/lib/Drupal/Core/StringTranslation/TranslatableMarkup.php
@@ -18,7 +18,7 @@
  * This is useful for using translation in very low level subsystems like entity
  * definition and stream wrappers.
  *
- * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+ * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
  * @see \Drupal\Core\StringTranslation\TranslationManager::translate()
  * @see \Drupal\Core\StringTranslation\TranslationManager::translateString()
  * @see \Drupal\Core\Annotation\Translation
@@ -65,14 +65,14 @@ class TranslatableMarkup extends FormattableMarkup {
    *   The string that is to be translated.
    * @param array $arguments
    *   (optional) An array with placeholder replacements, keyed by placeholder.
-   *   See \Drupal\Component\Render\FormattableMarkup::placeholderFormat() for
+   *   See \Drupal\Component\Render\FormattableMarkup::replacePlaceholders() for
    *   additional information about placeholders.
    * @param array $options
    *   (optional) An array of additional options.
    * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
    *   (optional) The string translation service.
    *
-   * @see \Drupal\Component\Render\FormattableMarkup::placeholderFormat()
+   * @see \Drupal\Component\Render\FormattableMarkup::replacePlaceholders()
    */
   public function __construct($string, array $arguments = array(), array $options = array(), TranslationInterface $string_translation = NULL) {
     $this->string = $string;
@@ -137,7 +137,7 @@ public function render() {
 
     // Handle any replacements.
     if ($args = $this->getArguments()) {
-      return $this->placeholderFormat($this->translatedMarkup, $args);
+      return $this->replacePlaceholders($this->translatedMarkup, $args);
     }
     return $this->translatedMarkup;
   }