6 uses of UNICODE_MULTIBYTE in Drupal 7

drupal_strlen in includes/unicode.inc

Counts the number of characters in a UTF-8 string.

drupal_strtolower in includes/unicode.inc

Lowercase a UTF-8 string.

drupal_strtoupper in includes/unicode.inc

Uppercase a UTF-8 string.

drupal_substr in includes/unicode.inc

Cuts off a piece of a string based on character indices and counts.

UnicodeUnitTest::testMbStringUnicode in modules/simpletest/tests/unicode.test

Test full unicode features implemented using the mbstring extension.

_unicode_check in includes/unicode.inc

Perform checks about Unicode support in PHP, and set the right settings if needed.