This DisplayString, up to 80 characters, holds the second transform in the IPSec Transform Set, and its description notes it is left as a zero-length string when no second transform is specified. An admin fills this in only when the transform set needs to layer a second mechanism, such as pairing an encryption transform with a separate authentication transform. For example, an admin pairing 'esp-3des' encryption with authentication might set this second slot to 'esp-sha-hmac', leaving it blank for transform sets that only need one algorithm.