uniCenta POS does not (as yet) have a "training mode" per se, but you can easily make a fresh installation on either a spare computer or (more probably) somewhere else on the same hard disk. I have installed Ubuntu 13.04 on another area of my hard disk and installed uniCenta on that region. You can also create "dummy" stock items. I reserved bar codes 1 through 10 for this purpose and made the bar codes match the fictitious product numbers of 1 through 10. When you are done experimenting you can make the items vanish by unchecking the box that says they should show up in the catalog.
