6 uses of UNICODE_MULTIBYTE

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.

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