diff --git a/dev-docs/bidders/gumgum.md b/dev-docs/bidders/gumgum.md
index 9906bc858f..dd2498d6ce 100644
--- a/dev-docs/bidders/gumgum.md
+++ b/dev-docs/bidders/gumgum.md
@@ -42,3 +42,7 @@ information.
 | `video`        | optional | Tracking ID       | `'ggumtest'`           | `string`  |
 | `videoPubID`   | optional | Publisher ID      | `123`                  | `integer` |
 | `inVideo`      | optional | Tracking ID       | `'ggumtest'`           | `string`  |
+
+
+Please note that both video and in-video products require a mediaType of video. 
+All other products (in-screen, slot, native) should have a mediaType of banner.
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