Correct Cyrillic encoding in PHP for MacOS

When creating CSV for Excel in Windows-1251 encoding (as used for the window), this file may not work correctly on the MacOS. Some Cyrillic characters are displayed incorrect (for example, letter "Я").

In this case you should use MacCyrillic encoding.

Example:

$converted_string = iconv('UTF-8', 'MacCyrillic', $string);