comment_loop_start action-hook . WP 2.2.0

Fires once the comment loop is started.

Usage

add_action( 'comment_loop_start', 'action_function_name_295' );
function action_function_name_295(){
	// action...
}

Where the hook is called

do_action( 'comment_loop_start' );

Where in WP core the hook is used WordPress