WordPress at a glance
filter is not described

the_password_form filter-hook . WP 2.7.0

Filters the HTML output for the protected post password form.

If modifying the password field, please note that the core database schema limits the password field to 20 characters regardless of the value of the size attribute in the form input.

Usage

add_filter( 'the_password_form', 'filter_function_name_7689' );
function filter_function_name_7689( $output ){
	// filter...

	return $output;
}
$output(string)
The password form HTML output.

Where the hook is called

get_the_password_form()
wp-includes/post-template.php 1633
return apply_filters( 'the_password_form', $output );

Where the hook is used (in WP core)

Does not used.