diff -u b/core/config/schema/core.data_types.schema.yml b/core/config/schema/core.data_types.schema.yml
--- b/core/config/schema/core.data_types.schema.yml
+++ b/core/config/schema/core.data_types.schema.yml
@@ -445,7 +445,7 @@
     case_sensitive:
       type: boolean
       label: 'Case sensitive'
-    is_trivial:
+    is_ascii:
       type: boolean
       label: 'Contains US ASCII characters only'
 
diff -u b/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
--- b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -443,7 +443,7 @@
           'description' => 'Primary Key: Unique cache ID.',
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
           'binary' => TRUE,
@@ -484,7 +484,7 @@
         'checksum' => array(
           'description' => 'The tag invalidation checksum when this entry was saved.',
           'type' => 'varchar',
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'length' => 255,
           'not null' => TRUE,
         ),
diff -u b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
--- b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseCacheTagsChecksum.php
@@ -177,7 +177,7 @@
           'description' => 'Namespace-prefixed tag string.',
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
         ),
diff -u b/core/lib/Drupal/Core/Config/DatabaseStorage.php b/core/lib/Drupal/Core/Config/DatabaseStorage.php
--- b/core/lib/Drupal/Core/Config/DatabaseStorage.php
+++ b/core/lib/Drupal/Core/Config/DatabaseStorage.php
@@ -194,7 +194,7 @@
           'description' => 'Primary Key: Config object collection.',
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
         ),
@@ -202,7 +202,7 @@
           'description' => 'Primary Key: Config object name.',
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
         ),
diff -u b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
--- b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
+++ b/core/lib/Drupal/Core/Database/Driver/mysql/Schema.php
@@ -144,7 +144,7 @@
       if (!empty($spec['binary'])) {
         $sql .= ' BINARY';
       }
-      if (!empty($spec['is_alphanumeric'])) {
+      if (!empty($spec['is_ascii'])) {
         $sql .= ' CHARACTER SET ascii COLLATE ascii_general_ci';
       }
     }
diff -u b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
--- b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
+++ b/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorageSchema.php
@@ -1603,7 +1603,7 @@
         'bundle' => array(
           'type' => 'varchar',
           'length' => 128,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
           'description' => 'The field instance bundle to which this row belongs, used when deleting a field instance',
@@ -1620,7 +1620,7 @@
         'langcode' => array(
           'type' => 'varchar',
           'length' => 32,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
           'description' => 'The language code for this data item.',
diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php
@@ -137,7 +137,7 @@
           // If the target entities act as bundles for another entity type,
           // their IDs should not exceed the maximum length for bundles.
           'length' => $target_type_info->getBundleOf() ? EntityTypeInterface::BUNDLE_MAX_LENGTH : 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
         ),
       );
     }
diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/LanguageItem.php
@@ -44,7 +44,7 @@
   public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
     $properties['value'] = DataDefinition::create('string')
       ->setLabel(t('Language code'))
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setRequired(TRUE);
 
     $properties['language'] = DataReferenceDefinition::create('language')
@@ -76,7 +76,7 @@
         'value' => array(
           'type' => 'varchar',
           'length' => 12,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
         ),
       ),
     );
diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/StringItem.php
@@ -32,7 +32,7 @@
   public static function defaultStorageSettings() {
     return array(
       'max_length' => 255,
-      'is_alphanumeric' => FALSE,
+      'is_ascii' => FALSE,
     ) + parent::defaultStorageSettings();
   }
 
@@ -46,7 +46,7 @@
           'type' => 'varchar',
           'length' => (int) $field_definition->getSetting('max_length'),
           'binary' => $field_definition->getSetting('case_sensitive'),
-          'is_alphanumeric' => $field_definition->getSetting('is_trivial'),
+          'is_ascii' => $field_definition->getSetting('is_ascii'),
         ),
       ),
     );
diff -u b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldType/UuidItem.php
@@ -30,7 +30,7 @@
   public static function defaultStorageSettings() {
     return array(
       'max_length' => 128,
-      'is_alphanumeric' => TRUE,
+      'is_ascii' => TRUE,
     ) + parent::defaultStorageSettings();
   }
 
diff -u b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
--- b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
+++ b/core/lib/Drupal/Core/Menu/MenuTreeStorage.php
@@ -1195,7 +1195,7 @@
           'description' => "The menu name. All links with the same menu name (such as 'tools') are part of the same menu.",
           'type' => 'varchar',
           'length' => 32,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => '',
         ),
@@ -1209,7 +1209,7 @@
           'description' => 'Unique machine name: the plugin ID.',
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
         ),
         'parent' => array(
@@ -1217,13 +1217,13 @@
           'type' => 'varchar',
           'length' => 255,
           'not null' => TRUE,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'default' => '',
         ),
         'route_name' => array(
           'description' => 'The machine name of a defined Symfony Route this menu item represents.',
           'type' => 'varchar',
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'length' => 255,
         ),
         'route_param_key' => array(
@@ -1287,7 +1287,7 @@
           'description' => 'The name of the module that generated this link.',
           'type' => 'varchar',
           'length' => DRUPAL_EXTENSION_NAME_MAX_LENGTH,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
           'not null' => TRUE,
           'default' => 'system',
         ),
diff -u b/core/modules/aggregator/src/Entity/Feed.php b/core/modules/aggregator/src/Entity/Feed.php
--- b/core/modules/aggregator/src/Entity/Feed.php
+++ b/core/modules/aggregator/src/Entity/Feed.php
@@ -226,7 +226,7 @@
 
     $fields['hash'] = BaseFieldDefinition::create('string')
       ->setLabel(t('Hash'))
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setDescription(t('Calculated hash of the feed data, used for validating cache.'));
 
     $fields['etag'] = BaseFieldDefinition::create('string')
diff -u b/core/modules/ban/ban.install b/core/modules/ban/ban.install
--- b/core/modules/ban/ban.install
+++ b/core/modules/ban/ban.install
@@ -22,7 +22,7 @@
         'description' => 'IP address',
         'type' => 'varchar',
         'length' => 40,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
diff -u b/core/modules/comment/comment.install b/core/modules/comment/comment.install
--- b/core/modules/comment/comment.install
+++ b/core/modules/comment/comment.install
@@ -50,7 +50,7 @@
         'not null' => TRUE,
         'default' => 'node',
         'length' => EntityTypeInterface::ID_MAX_LENGTH,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'description' => 'The entity_type of the entity to which this comment is a reply.',
       ),
       'field_name' => array(
@@ -58,7 +58,7 @@
         'not null' => TRUE,
         'default' => '',
         'length' => FieldStorageConfig::NAME_MAX_LENGTH,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'description' => 'The field_name of the field that was used to add this comment.',
       ),
       'cid' => array(
diff -u b/core/modules/comment/src/Entity/Comment.php b/core/modules/comment/src/Entity/Comment.php
--- b/core/modules/comment/src/Entity/Comment.php
+++ b/core/modules/comment/src/Entity/Comment.php
@@ -303,7 +303,7 @@
     $fields['entity_type'] = BaseFieldDefinition::create('string')
       ->setLabel(t('Entity type'))
       ->setDescription(t('The entity type to which this comment is attached.'))
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setSetting('max_length', EntityTypeInterface::ID_MAX_LENGTH);
 
     $fields['comment_type'] = BaseFieldDefinition::create('entity_reference')
@@ -314,7 +314,7 @@
     $fields['field_name'] = BaseFieldDefinition::create('string')
       ->setLabel(t('Comment field name'))
       ->setDescription(t('The field name through which this comment was added.'))
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setSetting('max_length', FieldStorageConfig::NAME_MAX_LENGTH);
 
     return $fields;
diff -u b/core/modules/dblog/dblog.install b/core/modules/dblog/dblog.install
--- b/core/modules/dblog/dblog.install
+++ b/core/modules/dblog/dblog.install
@@ -29,7 +29,7 @@
         'length' => 64,
         'not null' => TRUE,
         'default' => '',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'description' => 'Type of log message, for example "user" or "page not found."',
       ),
       'message' => array(
@@ -74,7 +74,7 @@
         'length' => 128,
         'not null' => TRUE,
         'default' => '',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'description' => 'Hostname of the user who triggered the event.',
       ),
       'timestamp' => array(
diff -u b/core/modules/file/file.install b/core/modules/file/file.install
--- b/core/modules/file/file.install
+++ b/core/modules/file/file.install
@@ -22,7 +22,7 @@
         'description' => 'The name of the module that is using the file.',
         'type' => 'varchar',
         'length' => DRUPAL_EXTENSION_NAME_MAX_LENGTH,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -30,14 +30,14 @@
         'description' => 'The name of the object type in which the file is used.',
         'type' => 'varchar',
         'length' => 64,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
       'id' => array(
         'description' => 'The primary key of the object using the file.',
         'type' => 'varchar',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'length' => 64,
         'not null' => TRUE,
         'default' => 0,
diff -u b/core/modules/file/src/Entity/File.php b/core/modules/file/src/Entity/File.php
--- b/core/modules/file/src/Entity/File.php
+++ b/core/modules/file/src/Entity/File.php
@@ -254,7 +254,7 @@
 
     $fields['filemime'] = BaseFieldDefinition::create('string')
       ->setLabel(t('File MIME type'))
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setDescription(t("The file's MIME type."));
 
     $fields['filesize'] = BaseFieldDefinition::create('integer')
diff -u b/core/modules/locale/locale.install b/core/modules/locale/locale.install
--- b/core/modules/locale/locale.install
+++ b/core/modules/locale/locale.install
@@ -69,7 +69,7 @@
       'context' => array(
         'type' => 'varchar',
         'length' => 255,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
         'description' => 'The context this string applies to.',
@@ -77,7 +77,7 @@
       'version' => array(
         'type' => 'varchar',
         'length' => 20,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => 'none',
         'description' => 'Version of Drupal where the string was last used (for locales optimization).',
@@ -107,7 +107,7 @@
       'language' => array(
         'type' => 'varchar',
         'length' => 12,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
         'description' => 'Language code. References {language}.langcode.',
@@ -147,7 +147,7 @@
       'type' => array(
         'type' => 'varchar',
         'length' => 50,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
         'description' => 'The location type (file, config, path, etc).',
@@ -162,7 +162,7 @@
       'version' => array(
         'type' => 'varchar',
         'length' => 20,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => 'none',
         'description' => 'Version of Drupal where the location was found.',
@@ -188,7 +188,7 @@
         'type' => 'varchar',
         'length' => '255',
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
         'description' => 'A unique short name to identify the project the file belongs to.',
       ),
@@ -196,7 +196,7 @@
         'type' => 'varchar',
         'length' => '12',
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
         'description' => 'Language code of this translation. References {language}.langcode.',
       ),
diff -u b/core/modules/menu_link_content/src/Entity/MenuLinkContent.php b/core/modules/menu_link_content/src/Entity/MenuLinkContent.php
--- b/core/modules/menu_link_content/src/Entity/MenuLinkContent.php
+++ b/core/modules/menu_link_content/src/Entity/MenuLinkContent.php
@@ -250,7 +250,7 @@
       ->setLabel(t('Bundle'))
       ->setDescription(t('The content menu link bundle.'))
       ->setSetting('max_length', EntityTypeInterface::BUNDLE_MAX_LENGTH)
-      ->setSetting('is_trivial', TRUE)
+      ->setSetting('is_ascii', TRUE)
       ->setReadOnly(TRUE);
 
     $fields['title'] = BaseFieldDefinition::create('string')
@@ -293,7 +293,7 @@
       ->setLabel(t('Menu name'))
       ->setDescription(t('The menu name. All links with the same menu name (such as "tools") are part of the same menu.'))
       ->setDefaultValue('tools')
-      ->setSetting('is_trivial', TRUE);
+      ->setSetting('is_ascii', TRUE);
 
     $fields['link'] = BaseFieldDefinition::create('link')
       ->setLabel(t('Link'))
diff -u b/core/modules/node/node.install b/core/modules/node/node.install
--- b/core/modules/node/node.install
+++ b/core/modules/node/node.install
@@ -56,7 +56,7 @@
         'description' => 'The {language}.langcode of this node.',
         'type' => 'varchar',
         'length' => 12,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -79,7 +79,7 @@
         'type' => 'varchar',
         'length' => 255,
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
       ),
       'grant_view' => array(
diff -u b/core/modules/search/search.install b/core/modules/search/search.install
--- b/core/modules/search/search.install
+++ b/core/modules/search/search.install
@@ -22,7 +22,7 @@
       'langcode' => array(
         'type' => 'varchar',
         'length' => '12',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'description' => 'The {languages}.langcode of the item variant.',
         'default' => '',
@@ -30,7 +30,7 @@
       'type' => array(
         'type' => 'varchar',
         'length' => 64,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'description' => 'Type of item, e.g. node.',
       ),
@@ -71,7 +71,7 @@
       'langcode' => array(
         'type' => 'varchar',
         'length' => '12',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'description' => 'The {languages}.langcode of the item variant.',
         'default' => '',
@@ -79,7 +79,7 @@
       'type' => array(
         'type' => 'varchar',
         'length' => 64,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'description' => 'The {search_dataset}.type of the searchable item to which the word belongs.',
       ),
diff -u b/core/modules/shortcut/shortcut.install b/core/modules/shortcut/shortcut.install
--- b/core/modules/shortcut/shortcut.install
+++ b/core/modules/shortcut/shortcut.install
@@ -24,7 +24,7 @@
         'length' => 32,
         'not null' => TRUE,
         'default' => '',
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'description' => "The {shortcut_set}.set_name that will be displayed for this user.",
       ),
     ),
diff -u b/core/modules/simpletest/simpletest.install b/core/modules/simpletest/simpletest.install
--- b/core/modules/simpletest/simpletest.install
+++ b/core/modules/simpletest/simpletest.install
@@ -130,7 +130,7 @@
         'type' => 'varchar',
         'length' => 255,
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
         'description' => 'The message group this message belongs to. For example: warning, browser, user.',
       ),
diff -u b/core/modules/system/database.api.php b/core/modules/system/database.api.php
--- b/core/modules/system/database.api.php
+++ b/core/modules/system/database.api.php
@@ -293,7 +293,7 @@
  *       'varchar' or 'text' fields to use case-sensitive binary collation.
  *       This has no effect on other database types for which case sensitivity
  *       is already the default behavior.
- *     - 'is_alphanumeric': A boolean indicating that MySQL should use
+ *     - 'is_ascii': A boolean indicating that MySQL should use
  *       ASCII character encoding for the field. This helps index usage be
  *       more efficient, and should be used on machine name fields.
  *     All parameters apart from 'type' are optional except that type
diff -u b/core/modules/system/src/Tests/Database/SchemaTest.php b/core/modules/system/src/Tests/Database/SchemaTest.php
--- b/core/modules/system/src/Tests/Database/SchemaTest.php
+++ b/core/modules/system/src/Tests/Database/SchemaTest.php
@@ -49,11 +49,11 @@
           'default' => "'\"funky default'\"",
           'description' => 'Schema column description for string.',
         ),
-        'test_field_string_is_alphanumeric'  => array(
+        'test_field_string_is_ascii'  => array(
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
-          'description' => 'Schema column description for is_alphanumeric string.',
+          'is_ascii' => TRUE,
+          'description' => 'Schema column description for is_ascii string.',
         ),
       ),
     );
@@ -74,7 +74,7 @@
       if ($column->Field == 'test_field_string') {
         $this->assertTrue($column->Collation == 'utf8_general_ci');
       }
-      if ($column->Field == 'test_field_string_is_alphanumeric') {
+      if ($column->Field == 'test_field_string_is_ascii') {
         $this->assertTrue($column->Collation == 'ascii_general_ci');
       }
     }
diff -u b/core/modules/system/system.install b/core/modules/system/system.install
--- b/core/modules/system/system.install
+++ b/core/modules/system/system.install
@@ -687,7 +687,7 @@
         'description' => "A string token generated against the current user's session id and the batch id, used to ensure that only the user who submitted the batch can effectively access it.",
         'type' => 'varchar',
         'length' => 64,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
       ),
       'timestamp' => array(
@@ -720,7 +720,7 @@
         'description' => 'Name of event (e.g. contact).',
         'type' => 'varchar',
         'length' => 64,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -728,7 +728,7 @@
         'description' => 'Identifier of the visitor, such as an IP address or hostname.',
         'type' => 'varchar',
         'length' => 128,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -830,7 +830,7 @@
         'type' => 'varchar',
         'length' => 255,
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
         'description' => 'The queue name.',
       ),
@@ -868,7 +868,7 @@
         'description' => 'Primary Key: Machine name of this route',
         'type' => 'varchar',
         'length' => 255,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -918,7 +918,7 @@
         'description' => 'Primary Key: Unique name.',
         'type' => 'varchar',
         'length' => 255,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => ''
       ),
@@ -969,14 +969,14 @@
         'description' => "A session ID (hashed). The value is generated by Drupal's session handlers.",
         'type' => 'varchar',
         'length' => 128,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
       ),
       'hostname' => array(
         'description' => 'The IP address that last used this session ID (sid).',
         'type' => 'varchar',
         'length' => 128,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -1035,7 +1035,7 @@
         'description' => "The language code this alias is for; if 'und', the alias will be used for unknown languages. Each Drupal path can have an alias for each supported language.",
         'type' => 'varchar',
         'length' => 12,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextLongItem.php b/core/modules/text/src/Plugin/Field/FieldType/TextLongItem.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextLongItem.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextLongItem.php
@@ -36,7 +36,7 @@
         'format' => array(
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
         ),
       ),
       'indexes' => array(
diff -u b/core/modules/text/src/Plugin/Field/FieldType/TextWithSummaryItem.php b/core/modules/text/src/Plugin/Field/FieldType/TextWithSummaryItem.php
--- b/core/modules/text/src/Plugin/Field/FieldType/TextWithSummaryItem.php
+++ b/core/modules/text/src/Plugin/Field/FieldType/TextWithSummaryItem.php
@@ -70,7 +70,7 @@
         'format' => array(
           'type' => 'varchar',
           'length' => 255,
-          'is_alphanumeric' => TRUE,
+          'is_ascii' => TRUE,
         ),
       ),
       'indexes' => array(
diff -u b/core/modules/user/user.install b/core/modules/user/user.install
--- b/core/modules/user/user.install
+++ b/core/modules/user/user.install
@@ -23,7 +23,7 @@
         'description' => 'The name of the module declaring the variable.',
         'type' => 'varchar',
         'length' => DRUPAL_EXTENSION_NAME_MAX_LENGTH,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'not null' => TRUE,
         'default' => '',
       ),
@@ -32,7 +32,7 @@
         'type' => 'varchar',
         'length' => 128,
         'not null' => TRUE,
-        'is_alphanumeric' => TRUE,
+        'is_ascii' => TRUE,
         'default' => '',
       ),
       'value' => array(