What are all usable autoblogging tags?

$unique_id;
$title;
$description;
$img;
$url;
$last_update;
$price;
$priceOld;
$percentageSaved;
$currency;
$currencyCode;
$manufacturer;
$category;
$merchant;
$logo;
$domain;
$rating;
$reviewsCount;
$availability;
$orig_url;
$ean;
$upc;
$sku;
$isbn;
$stock_status;
$group;