diff --git a/include/nuttx/nx/nx.h b/include/nuttx/nx/nx.h
index b17f91923e9..fa56e4dd55a 100644
--- a/include/nuttx/nx/nx.h
+++ b/include/nuttx/nx/nx.h
@@ -149,8 +149,8 @@ struct nx_callback_s
    *            the overall display
    *   bounds - The bounding rectangle that the describes the entire
    *            display
-   *   arg  - User provided argument (see nx_openwindow, nx_requestbkgd,
-   *          nxtk_openwindow, or nxtk_opentoolbar)
+   *   arg    - User provided argument (see nx_openwindow, nx_requestbkgd,
+   *            nxtk_openwindow, or nxtk_opentoolbar)
    *
    * Returned Value:
    *   None
@@ -172,8 +172,8 @@ struct nx_callback_s
    *   hwnd    - Window handle
    *   pos     - The (x,y) position of the mouse
    *   buttons - See NX_MOUSE_* definitions
-   *   arg  - User provided argument (see nx_openwindow, nx_requestbkgd,
-   *          nxtk_openwindow, or nxtk_opentoolbar)
+   *   arg     - User provided argument (see nx_openwindow, nx_requestbkgd,
+   *             nxtk_openwindow, or nxtk_opentoolbar)
    *
    * Returned Value:
    *   None
diff --git a/include/nuttx/nx/nxbe.h b/include/nuttx/nx/nxbe.h
index 0b30cbdadc7..4d3ae3e7ece 100644
--- a/include/nuttx/nx/nxbe.h
+++ b/include/nuttx/nx/nxbe.h
@@ -171,7 +171,10 @@ struct nxbe_window_s
                                        */
 #endif
 
-  /* Client state information this is provide in window callbacks */
+  /* Client state information this is provide in window callbacks
+   * Set by nx_openwindow, nx_requestbkgd, nxtk_openwindow, or
+   * nxtk_opentoolbar and persists for the life of the window.
+   */
 
   FAR void *arg;
 };