12 uses of REQUIREMENT_WARNING

color_requirements in drupal/core/modules/color/color.install
Implements hook_requirements().
drupal_requirements_url in drupal/core/includes/install.inc
Returns a URL for proceeding to the next page after a requirements problem.
image_requirements in drupal/core/modules/image/image.install
Implements hook_requirements() to check the PHP GD Library.
install_display_requirements in drupal/core/includes/install.core.inc
Displays installation requirements.
locale_requirements in drupal/core/modules/locale/locale.install
Implements hook_requirements().
system_requirements in drupal/core/modules/system/system.install
Test and report Drupal installation requirements.
unicode_requirements in drupal/core/includes/unicode.inc
Returns Unicode library status and errors.
update_check_requirements in drupal/core/update.php
Checks update requirements and reports errors and (optionally) warnings.
update_page_build in drupal/core/modules/update/update.module
Implements hook_page_build().
update_requirements in drupal/core/modules/update/update.install
Implements hook_requirements().
update_script_test_requirements in drupal/core/modules/system/tests/modules/update_script_test/update_script_test.install
Implements hook_requirements().
_update_requirement_check in drupal/core/modules/update/update.install
Fills in the requirements array.