The following schema describes the JSON data structure for an ISPF panel display:

{
  "PNL":{
    "description":"ISPF panel display data and format",
    "type":"object",
    "properties":{
      "VER":{
        "description":"ISPF panel JSON version identifier",
        "type":"string",
        "maxLength":4,
        "required":true
      },
      "NME":{
        "description":"Panel name",
        "type":"string",
        "maxLength":8,
        "required":true
      },
      "SCR":{
        "description":"ISPF logical screen identifier",
        "type":"string",
        "maxLength":1,
        "required":true
      },
      "SCN":{
        "description":"Screen name defined for this panel",
        "type":"string",
        "maxLength":8
      },
      "HDL":{
        "description":"Handle value - used internally by ISPF",
        "type":"string",
        "maxLength":12,
        "required":true
      },
      "RWS":{
        "description":"Panel height - number of rows",
        "type":"integer",
        "maximum":204,
        "required":true
      },
      "CLS":{
        "description":"Panel width - number of columns",
        "type":"integer",
        "maximum":160,
        "required":true
      },
      "TLE":{
        "description":"Panel title",
        "type":"string"
      },
      "EDT":{
        "description":"Edit data display indicator",
        "type":"string",
        "enum":["TRUE"]
      },
      "CML":{
        "description":"Command line location",
        "type":"string",
        "enum":["BOTTOM","ASIS","NONE"],
        "required":true
      },
      "ALA":{
        "description":"Indicates an alarm should sound when the panel is displayed",
        "type":"string",
        "enum":["TRUE"]
      },
      "CUR":{
        "description":"The cursor location on the panel",
        "type":"object",
        "required":true,
        "properties":{
          "ROW":{
            "description":"The number of the panel row the cursor is on",
            "type":"integer",
            "maximum":204,
            "required":true
          },
          "CLM":{
            "description":"The number of the panel column the cursor is on",
            "type":"integer",
            "maximum":160,
            "required":true
          }
        }
      },
      "SUP":{
        "description":"Indicates the current panel display can be scrolled up",
        "type":"string",
        "enum":["TRUE"]
      },
      "SDN":{
        "description":"Indicates the current panel display can be scrolled down",
        "type":"string",
        "enum":["TRUE"]
      },
      "SLF":{
        "description":"Indicates the current panel display can be scrolled left",
        "type":"string",
        "enum":["TRUE"]
      },
      "SRG":{
        "description":"Indicates the current panel display can be scrolled right",
        "type":"string",
        "enum":["TRUE"]
      },
      "IFY":{
        "description":"Identifiers currently active for this panel display",
        "type":"object",
        "required":true,
        "properties":{
          "SYS":{
            "description":"The system ID currently displayed with the panel",
            "type":"string",
            "maxLength":8,
            "required":true
          },
          "UID":{
            "description":"The user ID currently displayed with the panel",
            "type":"string",
            "maxLength":8,
            "required":true
          },
          "PNL":{
            "description":"Indicates that the panel name is currently displayed with the panel",
            "type":"string",
            "enum":["TRUE"]
          },
          "SCR":{
            "description":"Indicates that the screen ID is currently displayed with the panel",
            "type":"string",
            "enum":["TRUE"]
          }
        }
      },
      "MSG":{
        "description":"Details of a message displayed with the panel",
        "type":"object",
        "properties":{
          "ID":{
            "description":"The message identifier",
            "type":"string",
            "maxLength":8
          },
          "TYP":{
            "description":"The message type as defined on the TYPE keyword for the message",
            "type":"string",
            "maxLength":1,
            "enum":["N","W","A","C"]
          },
          "HLP":{
            "description":"Indicates there is no help associated with this message
(i.e. no help panel or long message for a short message)",
            "type":"string"
          },
          "LEN":{
            "description":"Length of the message text",
            "type":"integer"
          },
          "TXT":{
            "description":"The text for the message",
            "type":"string",
            "maxLength":512
          }
        }
      },
      "ARE":{
        "description":"The scrollable, dynamic, and table model areas defined for the panel",
        "type":"array",
        "items":{
          "NME":{
            "description":"The name used to define to dynamic or scrollable area.
For a table model area this is the table name.",
            "type":"string",
            "maxLength":8
          },
          "TYP":{
            "description":"The type of area - D=dynamic, S=scrollable, T=table model",
            "type":"string",
            "maxLength":1,
            "enum":["D","S","T"]
          },
          "TOP":{
            "description":"The panel row where the top of this area is located",
            "type":"integer"
          },
          "BOT":{
            "description":"The panel row where the bottom of this area is located",
            "type":"integer"
          },
          "LFT":{
            "description":"The panel row where the left side of this area is located",
            "type":"integer"
          },
          "RGT":{
            "description":"The panel row where the right side of this area is located",
            "type":"integer"
          }
        }
      },
      "CHA":{
        "description":"The color and highlighting defined for the character level attributes
to be used in the dynamic areas for the panel",
        "type":"array",
        "items":{
          "COL":{
            "description":"The color assigned for this character level attribute",
            "type":"string",
            "enum":["AQUA","BLUE","GREEN","PINK","RED","WHITE","YELLOW"]
          },
          "HIL":{
            "description":"The highlighting assigned for this character level attribute",
            "type":"string",
            "enum":["BLINK","RVIDEO","USCORE"]
          }
        }
      },
      "MNU":{
        "description":"The action bar choices and pull-down menus for the panel",
        "type":"array",
        "items":{
          "PUL":{
            "description":"Pull-down menu description text",
            "type":"string"
          },
          "CHS":{
            "description":"The choices for the pull-down menu",
            "type":"array",
            "items":{
              "N":{
                "description":"Pull-down choice description text",
                "type":"string"
              },
              "I":{
                "description":"An identifier used to indicate when the pull-down choice has
                been selected",
                "type":"string"
              }
            }
          }
        }
      },
      "FLD":{
        "description":"The input, output, point-and-shoot, and text fields displayed on the panel",
        "type":"array",
        "items":{
          "T":{
            "description":"The field type - I=input, O=output, P=point-and-shoot, T=text",
            "type":"string",
            "enum":["I","O","P","T"]
          },
          "P":{
            "description":"Indicates this input field is also a point-and-shoot field",
            "type":"string",
            "enum":["TRUE"]
          },
          "Z":{
            "description":"Indicates this is the command field for the panel",
            "type":"string",
            "enum":["TRUE"]
          },
          "A":{
            "description":"The name of the scrollable, dynamic, or table model area
            where this field is located",
            "type":"string",
            "maxLength":8
          },
          "Y":{
            "description":"The panel row where the field is located",
            "type":"integer",
            "maximum":204
          },
          "X":{
            "description":"The panel column where the field is located",
            "type":"integer",
            "maximum":160
          },
          "C":{
            "description":"The color of the field",
            "type":"string",
            "enum":["AQUA","BLUE","GREEN","PINK","RED","WHITE","YELLOW"]
          },
          "I":{
            "description":"The intensity of the field",
            "type":"string",
            "enum":["HIGH","LOW","NON"]
          },
          "H":{
            "description":"The highlighting for the field",
            "type":"string",
            "enum":["BLINK","RVIDEO","USCORE"]
          },
          "L":{
            "description":"The length of the field",
            "type":"integer"
          },
          "LX":{
            "description":"The total length for a scrollable field",
            "type":"integer",
            "maximum":32767
          },
          "N":{
            "description":"The name associated with the field",
            "type":"string",
            "maxLength":14
          },
          "D":{
            "description":"The data for the field",
            "type":"string",
            "maxLength":32767
          },
          "SL":{
            "description":"Identifies a selection field defined as a check box or radio button",
            "type":"object",
            "properties":{
              "T":{
                "description":"Type of selection field - CB=check box, RD=radio button",
                "type":"string",
                "enum":["CB","RD"]
              },
              "V":{
                "description":"The data value associated with selecting this field",
                "type":"string"
              },
              "N":{
                "description":"For a radio button selection, the name of the input field to
be updated with the associated value",
                "type":"string",
                "maxLength":8
              },
              "G":{
                "description":"For a radio button selection, the group number used to
identify related selection fields",
                "type":"integer",
                "maximum":99
              }
            }
          },
          "SHS":{
            "description":"For a field in a dynamic area, identifies the sections of the
field that are highlighted using character level (shadow) attributes",
            "type":"array",
            "items":{
              "STA":{
                "description":"The starting position within the field for a set of
characters highlighted by a character level attribute",
                "type":"integer"
              },
              "LEN":{
                "description":"The number of characters from the starting position that are
highlighted by the character level attribute",
                "type":"integer"
              },
              "ATT":{
                "description":"The number identifying the entry in the \"CHA\" array (see
above) for the character level attribute used to highlight this section of the field",
                "type":"integer"
              }
            }
          }
        }
      },
      "KEY":{
        "description":"The function keys defined for display with this panel",
        "type":"array",
        "items":{
          "K":{
            "description":"The function key identifier",
            "type":"string",
            "enum":["ENTER","1","2","3","4","5","6","7","8","9","11","12","13","14","15",
            "16","17","18","19","20","21","22","23","24"]
          },
          "N":{
            "description":"The label defined for the function key",
            "type":"string"
          }
        }
      }
    }
  }
}