Hide the WordPress version number

// Remove the generator tag from the page head and feeds.
add_filter( 'the_generator', '__return_empty_string' );

// Replace ?ver=<WordPress version> on scripts and styles with a site-specific hash.
function snipfire_hide_wp_version_in_urls( $src ) {
	$query = wp_parse_url( (string) $src, PHP_URL_QUERY );
	if ( ! $query ) {
		return $src;
	}

	parse_str( $query, $args );
	$version = get_bloginfo( 'version' );

	if ( isset( $args['ver'] ) && $args['ver'] === $version ) {
		// Still changes on every update, so browser caches refresh.
		$src = add_query_arg( 'ver', substr( wp_hash( $version ), 0, 8 ), $src );
	}

	return $src;
}
add_filter( 'script_loader_src', 'snipfire_hide_wp_version_in_urls' );
add_filter( 'style_loader_src', 'snipfire_hide_wp_version_in_urls' );