WordPress at a glance
filter is not described

mce_buttons_2 filter-hook . WP 1.0

This filter is documented in wp-includes/class-wp-editor.php

Usage

add_filter( 'mce_buttons_2', 'filter_function_name_4766', 10, 2 );
function filter_function_name_4766( $toolbar2, $string ){
	// filter...

	return $toolbar2;
}
$toolbar2
-
$string
-

Where the hook is called

wp_tinymce_inline_scripts()
mce_buttons_2
_WP_Editors::editor_settings()
mce_buttons_2
wp-includes/script-loader.php 458
$toolbar2 = apply_filters( 'mce_buttons_2', $toolbar2, 'classic-block' );
wp-includes/class-wp-editor.php 698
$mce_buttons_2 = apply_filters( 'mce_buttons_2', $mce_buttons_2, $editor_id );

Where in WP core the hook is used WordPress

Usage not found.