Wayne, I just tested with my local copy of v 2014 PU 1. The ""/"" is not required or allowed when creating the item code in Miscellaneous Item Maintenance. Rather, enter the item code sans the slash and choose the type of non-inventory item you are creating (Misc, Charge, or Comment).
You still have to put the ""/"" in front of the item id in Sales Order entry to use the code.
Hope this helps.