---
pmMetaData: { presence: required, structure: [
  -pmHeader: {
    presence: required,
    structure: {
      nfType: {
        presence: required,
        comment: "nfType comment"
      }
    }
  },
  -pmFields: {
    presence: required,
    structure: {
      measChangeType: {
        presence: required,
        value: [added, modified, deleted],
        comment: "measChangeType comment"
      },
      measAdditionalFields: {
        presence: required,
        comment: "measAdditionalFields comment",
        structure: {
          vendorField1: {
            presence: required,
            value: [X, Y, Z],
            comment: "vendorField1 comment"
          },
          vendorField2: {
            presence: optional,
            value: [A, B],
            comment: "vendorField2 comment"
          }
        }
      }
    }
  }
]}
...