Hi anmansir,
Welcome to Auctiva! Our system does not currently support the "custom label" feature you are asking about, but we do have that on our list of things to consider adding when we are planning our future site updates.
However, if you are using our inventory tools to track your items, there is a field called "Custom ID" that serves a similar purpose. If you would like to learn more about our inventory system, I recommend checking out the tutorial on that topic on the following page:
http://www.auctiva.com/help/tutorials.aspxIf you have any additional questions or concerns, please feel free to contact our customer support team about this using the web form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx-Mike