Note: this list is generated by looking for the string for this theme hook, so it may include some references that are not actually using this theme hook.

EntityReferenceSelectionHandlerViews::settingsForm in core/modules/entityreference/plugins/selection/EntityReferenceSelectionHandlerViews.inc
Implements EntityReferenceHandler::settingsForm().
file_file_formatter_file_image_settings in core/modules/file/file.module
Implements hook_file_formatter_FORMATTER_settings().
system_theme in core/modules/system/system.module
Implements hook_theme().
token_example_example_form in modules/examples/token_example/token_example.module
Form builder; display lists of supported token entities and text to tokenize.