9F7D

Data Storage Summary 1 is an 8- or 16-byte value exchanged during the transaction that summarises the state of the card's Kernel 2 data-storage feature - a compact status report rather than the actual stored data itself, related to both the Requested Operator ID (9F5C) and Slot Availability (9F5F), both covered earlier, as part of the same feature's overall status-reporting picture. Its variable length, 8 or 16 bytes depending on which specific data-storage configuration a card runs, is itself informative: a terminal or analysis tool needs to determine which length a given card actually returns rather than assuming a fixed size, since treating a 16-byte summary as if it were 8 bytes, or vice versa, will misparse whatever tag happens to follow it in the same constructed template. Like the rest of the Kernel 2 data-storage family, its actual byte-level content beyond a status summary isn't detailed in this entry - a terminal that needs to interpret specific status codes within it should consult Mastercard's own Kernel 2 data-storage documentation rather than assume a universal layout. See EMV Contactless Book C-2.