Hi. Thanx for the free support. I followed by your [Cyr to Lat reloaded – transliteration of links and file names] Support | WordPress.org message.
Test sample:
wp_insert_term( ‘t’, ‘post_tag’ ); // Inserts new term
wp_insert_term( ‘t’, ‘post_tag’, array( ‘slug’ => ‘t-alternative’ ) ); //...