I would take it to mean as Jon described above. With regards to the span, if only one value is "reported," I would assume it is the longest overall span (for most people, this would be from the edge of the thumb hole to the edge of the ring finger grip). What the other finger span might be... who knows? Every person's hand is different. For a large number of people, the middle finger span is generally 1/8" shorter, however I have seen no difference, 1/16", 3/16", and actually the other way where the middle finger span was longer (only once). Without actually measuring a person's span, its a guess at best.
S^2
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