WordPress at a glance
filter is not described

user_trailingslashit filter-hook . WP 2.2.0

Filters the trailing-slashed string, depending on whether the site is set to use trailing slashes.

Usage

add_filter( 'user_trailingslashit', 'filter_function_name_6848', 10, 2 );
function filter_function_name_6848( $string, $type_of_url ){
	// filter...

	return $string;
}
$string(string)
URL with or without a trailing slash.
$type_of_url(string)
The type of URL being considered. Accepts 'single', 'single_trackback', 'single_feed', 'single_paged', 'commentpaged', 'paged', 'home', 'feed', 'category', 'page', 'year', 'month', 'day', 'post_type_archive'.

Where the hook is called

user_trailingslashit()
wp-includes/link-template.php 64
return apply_filters( 'user_trailingslashit', $string, $type_of_url );

Where the hook is used (in WP core)

Does not used.