There are some HeroMart products that have no in-game code an item. We have a few shirts (called "Legacy" shirts) that were created before 2010 and originally sold at www.Jinx.com. Once HeroMart opened in 2010, we stopped selling items via Jinx and started selling them via www.HeroMart.com.
If a shirt is a "Legacy" shirt, it is noted in the item description on HeroMart's site and that there is no in-game code and item.
There are also some other shirts that have no codes and other products that may be released in the future.