diff --git a/types/office-js-preview/index.d.ts b/types/office-js-preview/index.d.ts
index 98f16e074061c5..b31a5d6a9eb54e 100644
--- a/types/office-js-preview/index.d.ts
+++ b/types/office-js-preview/index.d.ts
@@ -24455,6 +24455,10 @@ declare namespace Office {
          *
          * **Important**
          *
+         * - The `errorMessageMarkdown` property is available for preview in Outlook on Mac starting in Version //TBD. To test the property, join the
+         * {@link https://techcommunity.microsoft.com/kb/microsoft-365-insider-kb/join-the-microsoft-365-insider-program-on-macos/4401756 | Microsoft 365 Insider program} and
+         * select the **Beta Channel** option to access Office beta builds.
+         *
          * - The formatted error message must be 500 characters or less.
          *
          * - For guidance on supported Markdown elements, see 
diff --git a/types/office-js/index.d.ts b/types/office-js/index.d.ts
index 453bd0d13b9813..e38394ec88a2af 100644
--- a/types/office-js/index.d.ts
+++ b/types/office-js/index.d.ts
@@ -23846,6 +23846,10 @@ declare namespace Office {
          *
          * **Important**
          *
+         * - The `errorMessageMarkdown` property is available for preview in Outlook on Mac starting in Version //TBD. To test the property, join the
+         * {@link https://techcommunity.microsoft.com/kb/microsoft-365-insider-kb/join-the-microsoft-365-insider-program-on-macos/4401756 | Microsoft 365 Insider program} and
+         * select the **Beta Channel** option to access Office beta builds.
+         *
          * - The formatted error message must be 500 characters or less.
          *
          * - For guidance on supported Markdown elements, see