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.