This read-only value is a unique, non-contiguous index (nominally between 1 and 65535) for a row of the Phase Two IPsec proposal table, with no other meaning beyond serving as an index. An admin uses it only to distinguish between multiple configured Phase Two proposals when walking the table, not to interpret any value from the number itself. For example, two different Phase Two proposals on the firewall might be indexed as 1 and 3, with no significance to the gap at 2.