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.

BackdropWebTestCase::handleForm in core/modules/simpletest/backdrop_web_test_case.php
Handle form input related to backdropPost(). Ensure that the specified fields exist and attempt to create POST data in the correct manner for the particular field type.
backdrop_common_theme in core/includes/common.inc
Provides theme registration for themes across .inc files.
comment_form_node_type_form_alter in core/modules/comment/comment.module
Implements hook_form_FORM_ID_alter().
DatabaseTasks::getFormOptions in core/includes/install.inc
Return driver specific configuration options.
dblog_form_system_logging_settings_alter in core/modules/dblog/dblog.module
Implements hook_form_FORM_ID_alter() for system_logging_settings().
email_field_widget_settings_form in core/modules/email/email.module
Implements hook_field_widget_settings_form().
EntityIDLayoutAccess::form in core/modules/layout/plugins/access/entity_id_layout_access.inc
EntityLayoutContext::form in core/modules/layout/plugins/context/entity_layout_context_handler.inc
Settings form for configuring this context item.
entityreference_field_widget_settings_form in core/modules/entityreference/entityreference.module
Implements hook_field_widget_settings_form().
FieldCrudTestCase::setUp in core/modules/field/tests/field.test
Sets up a Backdrop site for running functional and integration tests.
FieldExampleTest::createField in modules/examples/field_example/tests/field_example.test
Utility function to create fields on a content type.
FieldUIManageFieldsTestCase::testCardinalitySettings in core/modules/field_ui/tests/field_ui.test
Tests the cardinality settings of a field.
field_ui_field_edit_form in core/modules/field_ui/field_ui.admin.inc
Form constructor for the field instance settings form.
field_ui_field_edit_form in core/modules/field_ui/field_ui.admin.inc
Form constructor for the field instance settings form.
field_ui_field_edit_form_submit in core/modules/field_ui/field_ui.admin.inc
Form submission handler for field_ui_field_edit_form().
field_ui_field_edit_form_validate in core/modules/field_ui/field_ui.admin.inc
Form validation handler for field_ui_field_edit_form().
filter_editor_image_upload_settings_form in core/modules/filter/filter.admin.inc
Subform constructor to configure the text editor's image upload settings.
filter_format_editor_image_form in core/modules/filter/filter.pages.inc
Form callback: Display a form for inserting/editing an image.
FormElementTestCase::testPlaceHolderText in core/modules/simpletest/tests/form.test
Tests placeholder text for elements that support placeholders.
form_process_weight in core/includes/form.inc
Expands a weight element into a select element.
form_test_menu in core/modules/simpletest/tests/form_test.module
Implements hook_menu().
form_test_number in core/modules/simpletest/tests/form_test.module
Builds a form to test #type 'number' and 'range' validation.
form_test_placeholder_test in core/modules/simpletest/tests/form_test.module
Builds a form to test the placeholder attribute.
hook_field_formatter_settings_form in core/modules/field_ui/field_ui.api.php
Specify the form elements for a formatter's settings.
hook_field_settings_form in core/modules/field_ui/field_ui.api.php
Add settings to a field settings form.
hook_field_widget_settings_form in core/modules/field_ui/field_ui.api.php
Add settings to a widget settings form.
image_field_instance_settings_form in core/modules/image/image.field.inc
Implements hook_field_instance_settings_form().
image_gd_settings in core/modules/system/image.gd.inc
Retrieve settings for the GD2 toolkit.
image_resize_form in core/modules/image/image.admin.inc
Form structure for the image resize form.
image_rotate_form in core/modules/image/image.admin.inc
Form structure for the image rotate form.
layout_menu_item_form in core/modules/layout/layout.admin.inc
Form callback; Configure a layout menu item.
NumberFieldSettingsTestCase::testNumberDecimalFieldSettings in core/modules/field/modules/number/tests/number_settings.test
Test number_decimal field settings.
NumberFieldSettingsTestCase::testNumberIntegerFieldSettings in core/modules/field/modules/number/tests/number_settings.test
Test number_integer field settings.
NumberFieldTestCase::testNumberDecimalField in core/modules/field/modules/number/tests/number.test
Test number_decimal field.
NumberFieldTestCase::testNumberDecimalFieldStepValidation in core/modules/field/modules/number/tests/number.test
Test number_decimal field step validation.
NumberFieldTestCase::testNumberFieldEmpty in core/modules/field/modules/number/tests/number.test
Test empty value submission.
NumberFieldTestCase::testNumberFloatField in core/modules/field/modules/number/tests/number.test
Test number_float field.
NumberFieldTestCase::testNumberIntegerField in core/modules/field/modules/number/tests/number.test
Test number_integer field.
number_field_info in core/modules/field/modules/number/number.module
Implements hook_field_info().
number_field_widget_form in core/modules/field/modules/number/number.module
Implements hook_field_widget_form().
number_field_widget_info in core/modules/field/modules/number/number.module
Implements hook_field_widget_info().
path_patterns_settings_form in core/modules/path/path.admin.inc
Form builder; Configure the URL alias pattern settings.
search_admin_settings in core/modules/search/search.admin.inc
Menu callback: displays the search module settings page.
system_element_info in core/modules/system/system.module
Implements hook_element_info().
system_tokens in core/modules/system/system.tokens.inc
Implements hook_tokens().
system_token_info in core/modules/system/system.tokens.inc
Implements hook_token_info().
system_token_info in core/modules/system/system.tokens.inc
Implements hook_token_info().
TaxonomyTermDepthLayoutAccess::form in core/modules/taxonomy/layout/taxonomy_term_depth_access.inc
Settings form for configuring this access item.
taxonomy_form_term in core/modules/taxonomy/taxonomy.admin.inc
Form function for the term edit form.
text_field_formatter_settings_form in core/modules/field/modules/text/text.module
Implements hook_field_formatter_settings_form().
text_field_settings_form in core/modules/field/modules/text/text.module
Implements hook_field_settings_form().
text_field_widget_settings_form in core/modules/field/modules/text/text.module
Implements hook_field_widget_settings_form().
update_batch in core/includes/update.inc
Starts the database update batch process.
update_build_dependency_graph in core/includes/update.inc
Constructs a graph which encodes the dependencies between module updates.
update_resolve_dependencies in core/includes/update.inc
Resolves dependencies in a set of module updates, and orders them correctly.
update_script_selection_form in core/update.php
Form constructor for the list of available database module updates.
user_admin_settings in core/modules/user/user.admin.inc
Form builder; Configure user settings for this site.
ViewsBlock::form in core/modules/views/includes/views.block.inc
Build the settings form for editing this block.
ViewsUiBaseViewsWizard::build_form in core/modules/views_ui/wizards/views_ui_base_views_wizard.php
For AJAX callbacks to build other elements in the "show" form.
views_plugin_display_page::options_form in core/modules/views/plugins/views_plugin_display_page.inc
Provide the default form for setting options.
views_plugin_pager_full::options_form in core/modules/views/plugins/views_plugin_pager_full.inc
Provide the default form for setting options.
views_plugin_pager_none::options_form in core/modules/views/plugins/views_plugin_pager_none.inc
Provide the default form for setting options.
views_plugin_pager_some::options_form in core/modules/views/plugins/views_plugin_pager_some.inc
Provide the default form for setting options.
views_plugin_style_grid::options_form in core/modules/views/plugins/views_plugin_style_grid.inc
Render the given style.
_book_add_form_elements in core/modules/book/book.module
Builds the common elements of the book form for the node and outline forms.
_date_html5_field_widget_settings_form in core/modules/date/date.admin.inc
Custom callback to provide the HTML5 widget settings form.
_filter_url_settings in core/modules/filter/filter.module
Implements callback_filter_settings().
_form_test_disabled_elements in core/modules/simpletest/tests/form_test.module
Build a form to test disabled elements.