diff -u b/src/Plugin/Tamper/KeywordFilter.php b/src/Plugin/Tamper/KeywordFilter.php
--- b/src/Plugin/Tamper/KeywordFilter.php
+++ b/src/Plugin/Tamper/KeywordFilter.php
@@ -24,6 +24,8 @@
   const SETTING_EXACT = 'exact';
   const SETTING_CASE_SENSITIVE = 'case_sensitive';
   const SETTING_INVERT = 'invert';
+  const SETTING_WORD_LIST = 'word_list';
+  const SETTING_REGEX = 'regex';
 
   /**
    * {@inheritdoc}
@@ -42,11 +44,39 @@
    * {@inheritdoc}
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
-    $form[self::SETTING_OPERATION] = [
-      '#type' => 'select',
-      '#title' => $this->t('How to convert case'),
-      '#options' => $this->getOptions(),
-      '#default_value' => $this->getSetting(self::SETTING_OPERATION),
+    $form[self::SETTING_WORDS] = [
+      '#type' => 'textarea',
+      '#title' => $this->t('Words or phrases to filter on'),
+      '#default_value' => $this->getSetting(self::SETTING_WORDS),
+      '#description' => $this->t('A list of words/phrases that need to appear in the text. Enter one value per line.'),
+    ];
+
+    $form[self::SETTING_WORD_BOUNDARIES] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Respect word boundaries'),
+      '#default_value' => $this->getSetting(self::SETTING_WORD_BOUNDARIES),
+      '#description' => $this->t('If checked, then "book" will match "book" but not "bookcase".'),
+    ];
+
+    $form[self::SETTING_EXACT] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Exact'),
+      '#default_value' => $this->getSetting(self::SETTING_EXACT),
+      '#description' => $this->t('If checked, then "book" will only match "book". This will override the "Respect word boundaries" setting above.'),
+    ];
+
+    $form[self::SETTING_CASE_SENSITIVE] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Case sensitive'),
+      '#default_value' => $this->getSetting(self::SETTING_CASE_SENSITIVE),
+      '#description' => $this->t('If checked, then "book" will match "book" but not "Book" or "BOOK".'),
+    ];
+
+    $form[self::SETTING_INVERT] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Invert filter'),
+      '#default_value' => $this->getSetting(self::SETTING_INVERT),
+      '#description' => $this->t('Inverting the filter will remove items with the specified text.'),
     ];
 
     return $form;
@@ -57,23 +87,62 @@
    */
   public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
     parent::submitConfigurationForm($form, $form_state);
-    $this->setConfiguration([self::SETTING_OPERATION => $form_state->getValue(self::SETTING_OPERATION)]);
+    $this->setConfiguration([self::SETTING_WORDS => $form_state->getValue(self::SETTING_WORDS)]);
+    $this->setConfiguration([self::SETTING_WORD_BOUNDARIES => $form_state->getValue(self::SETTING_WORD_BOUNDARIES)]);
+    $this->setConfiguration([self::SETTING_EXACT => $form_state->getValue(self::SETTING_EXACT)]);
+    $this->setConfiguration([self::SETTING_CASE_SENSITIVE => $form_state->getValue(self::SETTING_CASE_SENSITIVE)]);
+    $this->setConfiguration([self::SETTING_INVERT => $form_state->getValue(self::SETTING_INVERT)]);
+    $this->setConfiguration([self::SETTING_WORD_LIST => $form_state->getValue(self::SETTING_WORD_LIST)]);
+    $this->setConfiguration([self::SETTING_REGEX => $form_state->getValue(self::SETTING_REGEX)]);
   }
 
   /**
-   * Get the case conversion options.
-   *
-   * @return array
-   *   List of options, keyed by method on Drupal's unicode class.
+   * {@inheritdoc}
    */
-  protected function getOptions() {
-    return [
-      'strtoupper' => $this->t('Convert to uppercase'),
-      'strtolower' => $this->t('Convert to lowercase'),
-      'ucfirst' => $this->t('Capitalize the first character'),
-      'lcfirst' => $this->t('Convert the first character to lowercase'),
-      'ucwords' => $this->t('Capitalize the first character of each word'),
-    ];
+  public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
+    if (strlen($form_state->getValue('phone_number')) < 3) {
+      $form_state->setErrorByName('phone_number', $this->t('The phone number is too short. Please enter a full phone number.'));
+    }
+    global $multibyte;
+    $is_multibyte = ($multibyte == UNICODE_MULTIBYTE) ? TRUE : FALSE;
+
+    $form_state->setValue(
+      self::SETTING_WORD_LIST,
+      str_replace("\r", '', $form_state->getValue(self::SETTING_WORDS))
+    );
+    $word_list = explode("\n", $form_state->getValue(self::SETTING_WORDS));
+    $word_list = array_map('trim', $word_list);
+    $form_state->setValue(
+      self::SETTING_WORD_LIST,
+      $word_list
+    );
+    $form_state->setValue(self::SETTING_REGEX, FALSE);
+
+    if (!empty($settings['exact']) || $settings['word_boundaries']) {
+      foreach ($settings['word_list'] as &$word) {
+        if (!empty($settings['exact'])) {
+          $word = '/^' . preg_quote($word, '/') . '$/u';
+        }
+        elseif ($settings['word_boundaries']) {
+          // Word boundaries can only match a word with letters at the end.
+          if (!preg_match('/^\w(.*\w)?$/u', $word)) {
+            form_set_error('settings][words', t('Search text must begin and end with a letter, number, or underscore to use the %option option.', array('%option' => t('Respect word boundaries'))));
+          }
+          $word = '/\b' . preg_quote($word, '/') . '\b/u';
+        }
+        if (!$settings['case_sensitive']) {
+          $word .= 'i';
+        }
+      }
+      $settings['regex'] = TRUE;
+    }
+    
+    elseif (!$settings['word_boundaries'] && $settings['case_sensitive']) {
+      $settings['func'] = $is_multibyte ? 'mb_strpos' : 'strpos';
+    }
+    elseif (!$settings['word_boundaries'] && !$settings['case_sensitive']) {
+      $settings['func'] = $is_multibyte ? 'mb_stripos' : 'stripos';
+    }
   }
 
   /**