json_schema: {
      "$schema": "http://json-schema.org/draft-04/schema#",
      "title": "ED3D systems and filters list",
      "type": "object",
      "categories": {
          "title": "Categories list to classify systems",
          "type": "object",
          "items": {
              "category": {
                  "title": "Category",
                  "type": "object",
                  "properties": {
                      "id": {
                          "description": "The category ID",
                          "type": "integer"
                      },
                      "name": {
                          "description": "The category title",
                          "type": "string"
                      },
                      "color": {
                          "type": "string"
                      }
                  },
                  "required": [
                      "id",
                      "name"
                  ]
              }
          }
      },
      "systems": {
          "title": "Systems list",
          "type": "array",
          "items": {
              "title": "System",
              "type": "object",
              "properties": {
                  "name": {
                      "description": "System name",
                      "type": "string"
                  },
                  "coords": {
                      "description": "System coordinates",
                      "type": "object",
                      "properties": {
                          "x": {
                              "description": "X coord",
                              "type": "integer"
                          },
                          "y": {
                              "description": "Y coord",
                              "type": "integer"
                          },
                          "z": {
                              "description": "Z coord",
                              "type": "integer"
                          }
                      },
                      "required": [
                          "x",
                          "y",
                          "z"
                      ]
                  },
                  "type": {
                      "description": "The stellar type: A, B, O...",
                      "type": "integer"
                  },
                  "infos": {
                      "description": "A custom description for the system",
                      "type": "string"
                  },
                  "cat": {
                      "description": "A list of categories for the system",
                      "type": "array",
                      "items": {
                          "id": {
                              "description": "A category ID",
                              "type": "integer"
                          }
                      }
                  }
              },
              "required": [
                  "name",
                  "coords"
              ]
          }
      },
      "required": [
          "categories.items.category",
          "systems"
      ],
      "properties": {
          "categories.items.category": {
              "$ref": "#/categories/items/category"
          },
          "systems": {
              "$ref": "#/systems"
          }
      }
  }