Be sure to check whether your chosen stacker has either these symbols to match your pallet type for easier material handling.
Open based pallet (without bottom boards)
This pallet is designed to be placed over forked stackers. It has no bottom boards for stackers to easily pick up the pallet. Typically, most handling equipment can handle this pallet type compared to closed based pallets.
Closed based pallet (with bottom boards)
A stacker with straddle legs can fit around this type of pallet. Position the forks between the legs then insert into the pallet when in use. The stacker can be used to handle both open based pallets and closed based pallets if a stacker is enlisted in this category.