diff --git a/content-style-guide.md b/content-style-guide.md
index 6bca8c4..d7c4063 100644
--- a/content-style-guide.md
+++ b/content-style-guide.md
@@ -1132,6 +1132,8 @@ Here are the various trademark symbols and when to use them:
   * back end (noun), back-end (adjective)  
   * beta  
   * checkbox  
+  * co-op
+  * cooperative
   * coworker
   * Cloudflare
   * double-click