The default group for module CSS files added to the page.

2 uses of CSS_DEFAULT
AJAXFrameworkTestCase::testLazyLoad in modules/simpletest/tests/ajax.test
Test that new JavaScript and CSS files added during an AJAX request are returned.
drupal_add_css in includes/
Adds a cascading stylesheet to the stylesheet queue.


includes/, line 65
Common functions that many Drupal modules will need to reference.


define('CSS_DEFAULT', 0)


iadegesso’s picture

Please, can you update this page and the ones of both CSS_THEME and CSS_SYSTEM in order to better explain the differences among these three constants?

Thanks a lot

Iade Gesso, MSc, PhD

KeyboardCowboy’s picture


These constants are defined together on the API reference for drupal_add_css(). Essentially they are a grouping mechanism to keep css files the the proper order: system, then default, then theme.