This DisplayString, up to 80 characters, holds the third transform in the IPSec Transform Set and, like the second slot, defaults to a zero-length string when unused. An admin uses this third slot only for transform sets that combine three distinct mechanisms, which is uncommon compared to the simpler one- or two-transform combinations. For example, an admin building an unusually layered transform set might populate this third slot with a compression transform such as 'comp-lzs' alongside the first two encryption/authentication slots.