This part of ISO/IEC 15026 specifies minimum requirements for the structure and contents of an assurance case. An assurance case includes a top-level claim for a property of a system or product (or set of claims)@ systematic argumentation regarding this claim@ and the evidence and explicit assumptions that underlie this argumentation. Arguing through multiple levels of subordinate claims@ this structured argumentation connects the top-level claim to the evidence and assumptions. This part of ISO/IEC 15026 does not place requirements on the quality of the contents of an assurance case. Rather@ it places requirements on the existence of the contents and structure of an assurance case. While several notations and slightly varying terminologies are currently used in practice@ this part of ISO/IEC 15026 does not require the use of a particular terminology or graphical representation. Likewise@ it places no requirements on the means of physical implementation of the data@ including no requirements for redundancy or co-location.