Remove h1 from the WordPress editor.

wp_remove_h1_from_editor.php

<?php
/**
 *  Remove the h1 tag from the WordPress editor.
 *
 *  @param   array  $settings  The array of editor settings
 *  @return  array             The modified edit settings
 */
function remove_h1_from_editor( $settings ) {
    $settings['block_formats'] = 'Paragraph=p;Heading 2=h2;Heading 3=h3;Heading 4=h4;Heading 5=h5;Heading 6=h6;Preformatted=pre;';
    return $settings;
}

Thanks! Very useful.

Missing:

add_filter( 'tiny_mce_before_init', 'remove_h1_from_editor' );