diff --git a/lib/ProgramCall.js b/lib/ProgramCall.js
index 6613315..2450f1d 100644
--- a/lib/ProgramCall.js
+++ b/lib/ProgramCall.js
@@ -103,8 +103,8 @@ class ProgramCall {
   * @property {string} value - The value of the data.
   * @property {string} [name] - The name of the parameter.
   * @property {data[]} [fields] - The array of data objects for a ds.
-  * @property {string} [io] - Whether the parameter is used for input, output, or both.
-  * Valid values are ``in``, ``out``, or ``both``.
+  * @property {string} [io] - Whether the parameter is used for input, output, both, or *OMIT.
+  * Valid values are ``in``, ``out``, ``both``, and ``omit``.
   * @property {string} [by] - Whether to pass the parameter by reference or value.
   * Valid values are ``ref`` or ``val``. NOTE: Pass by value requires ``XMLSERVICE >= 1.9.9.3``.
   * @property {string} [dim] - Sets ds array dimension value.