default callback function in wp_list_comments

The wp_list_comments() function uses the HTML comment list class Walker_Comment by default:

  • A single comment is then displayed with the Walker_Comment::comment() method (#source).

  • If the comment format is HTML5 then the Walker_Comment::html5_comment() is used instead (#source).

  • The pingbacks are rendered with the Walker_Comment::ping() method (#source).