This indicates whether the traffic on this SVC was negotiated as susceptible to 'clipping,' the leading or trailing truncation that can occur with certain compressed voice or variable-rate encodings when cells are lost or delayed, information exchanged during call setup rather than something the admin configures directly. An admin investigating quality complaints on a voice-over-ATM SVC would check this field to see whether the call was negotiated as susceptible(3), which would make it more sensitive to cell loss or delay variation the admin might otherwise dismiss as minor. For example, an SVC carrying compressed voice negotiated as susceptible(3) would show audible artifacts from cell loss that a not-susceptible(2) data SVC experiencing the same loss rate wouldn't exhibit at all.