The ONLY source of reliable data in in the data sheet. I could not see this parameter in the data sheet for that device. It looks like some sort of data extraction algorithm that has gone wrong.
Contact the distributors and ask them about it.
But as I said it might be the maximum voltage that ensures pull in as seen by this section of the data sheet:-
Note is says it is 70% of the nominal coil voltage which at 5V is 3.5V.