* 2 items of the same type can't be mixed except mushrooms.
* Butchered items can last for more than one creation.
* [http://imperialsoft69.co60.cc120.243/wurm/healingcovers.php Healing Cover Calculator] <!-- Link back up on a new host ~Solen -->
* When training [[natural substances]] skill by making covers, higher potency covers will give more skill.