This selects exactly which credential scheme -- serial number, password, logical ONU ID (LOID), or combinations, including 'All' variants that apply the rule to every currently pending discovered ONU at once -- is used to formally confirm and accept a discovered ONU into service. It's the tool an admin reaches for to bulk-approve a batch of newly-installed units in one action instead of confirming each one individually. For example, choosing snPwdAuthAll(7) approves every currently-discovered unit that matches on SN plus password in a single operation rather than one confirmation click per ONU.