StockState

Item stock state. If this field is unspecified, the item is assumed to be in stock.

Enums
STOCK_STATE_UNSPECIFIED Default item stock status. Should never be used.
IN_STOCK Item in stock.
OUT_OF_STOCK Item out of stock.
PREORDER Item that is in pre-order state.
BACKORDER Item that is back-ordered (i.e. temporarily out of stock).