An asset that is eligible to be delivered to the protection seller following a default or that can be used to provide the reference price for cash settlement. Any debt obligation that is pari passu or senior to the reference obligation counts as a deliverable obligation. (However, certain obligations, such as zero coupon bonds and those in minor currencies are usually excluded.) In this way, the reference obligation acts as a marker of the seniority of debt that is referenced in the credit default swap.