diff --git a/dev-docs/modules/userid-submodules/33across.md b/dev-docs/modules/userid-submodules/33across.md
index 8f1a851be9..cb05d24672 100644
--- a/dev-docs/modules/userid-submodules/33across.md
+++ b/dev-docs/modules/userid-submodules/33across.md
@@ -26,6 +26,7 @@ The following configuration parameters are available:
 | name | Required | String | The name of this sub-module | `"33acrossId"` |
 | params ||| Details for the sub-module initialization ||
 | params.pid | Required | String | Partner ID (PID) | Please reach out to [PrebidUIM@33across.com](mailto:PrebidUIM@33across.com) and request your PID |
+| params.storeFpid | Optional | Boolean | Indicates whether a supplemental first-party ID may be stored to improve addressability | `false` (default) or `true` |
 | storage |||||
 | storage.name | Required | String | The name of the cookie or html5 local storage key | `"33acrossId"` (recommended) |
 | storage.type | Required | String | This is where the 33across user ID will be stored | `"html5"` (recommended) or `"cookie"` |
@@ -40,7 +41,8 @@ pbjs.setConfig({
     userIds: [{
       name: "33acrossId",
       params: {
-        pid: "0010b00002GYU4eBAH" // Example ID
+        pid: "0010b00002GYU4eBAH", // Example ID
+        storeFpid: true
       },
       storage: {
         name: "33acrossId",