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.

backdrop_common_theme in core/includes/common.inc
Provides theme registration for themes across .inc files.
comment_admin_overview in core/modules/comment/comment.admin.inc
Form constructor for the comment overview administration form.
database_test_theme_tablesort in core/modules/simpletest/tests/database_test.module
Output a form without setting a header sort.
FormsElementsTableSelectFunctionalTest::testAjax in core/modules/simpletest/tests/form.test
Test presence of ajax functionality
FormsElementsTableSelectFunctionalTest::testMultipleFalseOptionChecker in core/modules/simpletest/tests/form.test
Test the whether the option checker gives an error on invalid tableselect values for radios.
FormsElementsTableSelectFunctionalTest::testMultipleFalseSubmit in core/modules/simpletest/tests/form.test
Test submission of values when #multiple is FALSE.
FormsElementsTableSelectFunctionalTest::testMultipleTrueOptionChecker in core/modules/simpletest/tests/form.test
Test the whether the option checker gives an error on invalid tableselect values for checkboxes.
installer_browser_installation_enable_form in core/modules/installer/installer.pages.inc
Form builder for the select versions form.
installer_manager_update_form in core/modules/installer/installer.manager.inc
Form constructor for the update form of the Installer module.
layout_settings_page in core/modules/layout/layout.admin.inc
Administrative form for layout settings.
redirect_list_form in core/modules/redirect/redirect.admin.inc
Form callback; Display the list of all redirects.
system_element_info in core/modules/system/system.module
Implements hook_element_info().
_form_test_tableselect_ajax_callback in core/modules/simpletest/tests/form_test.module
Ajax callback that returns the form element.
_form_test_tableselect_form_builder in core/modules/simpletest/tests/form_test.module
Build a form to test the tableselect element.
_form_test_tableselect_multiple_false_form_submit in core/modules/simpletest/tests/form_test.module
Process the tableselect #multiple = FALSE submitted values.
_form_test_tableselect_multiple_true_form_submit in core/modules/simpletest/tests/form_test.module
Process the tableselect #multiple = TRUE submitted values.
_form_validate in core/includes/form.inc
Performs validation on form elements.