This read-create INTEGER field holds the Tuple's first value slot, restricted to plain integer values, as opposed to the address or mask style values allowed in the second slot. An admin uses this when the classification match needs a simple numeric value, such as a protocol number or port number, rather than a structured address. For example, to match on TCP port 443, the admin would populate this integer-only field with the value 443 as part of the Tuple definition.