10 files declare their use of FieldFilteredMarkup in Zircon Profile 8

FieldConfigEditForm.php in core/modules/field_ui/src/Form/FieldConfigEditForm.php

Contains \Drupal\field_ui\Form\FieldConfigEditForm.

FieldFilteredMarkupTest.php in core/tests/Drupal/Tests/Core/Field/FieldFilteredMarkupTest.php

Contains \Drupal\Tests\Core\Field\FieldFilteredMarkupTest.

file.field.inc in core/modules/file/file.field.inc

Field module functionality for the File module.

FileWidget.php in core/modules/file/src/Plugin/Field/FieldWidget/FileWidget.php

Contains \Drupal\file\Plugin\Field\FieldWidget\FileWidget.

NumberListField.php in core/modules/options/src/Plugin/views/argument/NumberListField.php

Contains \Drupal\options\Plugin\views\argument\NumberListField.

NumberWidget.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/NumberWidget.php

Contains \Drupal\Core\Field\Plugin\Field\FieldWidget\NumberWidget.

OptionsDefaultFormatter.php in core/modules/options/src/Plugin/Field/FieldFormatter/OptionsDefaultFormatter.php

Contains \Drupal\options\Plugin\Field\FieldFormatter\OptionsDefaultFormatter.

OptionsKeyFormatter.php in core/modules/options/src/Plugin/Field/FieldFormatter/OptionsKeyFormatter.php

Contains \Drupal\options\Plugin\Field\FieldFormatter\OptionsKeyFormatter.

OptionsWidgetBase.php in core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/OptionsWidgetBase.php

Contains \Drupal\Core\Field\Plugin\Field\FieldWidget\OptionsWidgetBase.

StringListField.php in core/modules/options/src/Plugin/views/argument/StringListField.php

Contains \Drupal\options\Plugin\views\argument\StringListField.