A number of abbreviations are used to describe bulk carriers. "OBO" describes a bulk carrier that carries a combination of ore, bulk, and oil, and "O/O" is used for combination oil and ore carriers.[4] The terms "VLOC", "VLBC", "ULOC", and "ULBC" for very large and ultra-large ore and bulk carriers were adapted from the supertanker designations very large crude carrier and ultra-large crude carrier.[5]