Adding admin-defined product information to Commerce orders

[opentype]

I’m setting up a Commerce store to sell software licenses, which come with product-specific EULAs, which might change over time. 
Therefore I would like to save a version number with the purchase, so every order gets something like an “EULA Version 1.5” tag, and when the EULA changes future orders (and only those!) will all get “1.6” and so on. The custom fields come to mind to do this, but they are for selections/input from the user, not admin-defined information. 

Is there a stock option to this? I played around with it for a couple hours but I can’t find any way. The information should be added automatically, be easily visible/accessible (like Commerce custom fields are on the invoice or in the Manage Purchases section) and there should be a global way to switch to new numbers. I don’t want to manually edit 50 products every time the EULA changes.