This INTEGER is a unique index for each registration entry, ranging from 1 to cnt2RegistrationNum, with row order reflecting the chronological sequence in which subagents actually registered. An administrator can read that ordering to see which subagent registered first or last during startup, which is useful for diagnosing a slow-starting module. For example, finding a particular subagent's entry consistently last in cnt2RegisterIndex order after every reboot could explain a recurring delay before its data becomes available.