Where? I don't see that. What type info is below? Do you mean "mapList"? I suspect it's just what they chose to name the key.

  "triestimes": 3,
     "mapList": [
       {
           "desc": "ftp",
           "nExternalPort": 6221,
           "nInternalPort": 21,
           "sProtocol": "TCP",
           "bEnable": 0
       },...