I can't find the info right now.
From memory, you can but you can't mention it in the listing.
So in other words you can put your own made vouchers in the parcel for next time but cannot solicit the voucher to sell items.
Then when the buyer wants to buy next time you tell them to let you know which items so you can revise the price of the item/s before they purchase.
BTW, not eBay here, only volunteer members.
