diff --git a/doc/development/service_ping/index.md b/doc/development/service_ping/index.md
index cd702720319bc505914848c0cb8779bda83472c8..152eec87d5d9d80d2a80c310ba0428e872fddffb 100644
--- a/doc/development/service_ping/index.md
+++ b/doc/development/service_ping/index.md
@@ -50,6 +50,8 @@ We use the following terminology to describe the Service Ping components:
 - **Metrics**: primarily made up of row counts for different tables in an instance's database. Each
   metric has a corresponding [metric definition](metrics_dictionary.md#metrics-definition-and-validation)
   in a YAML file.
+- **MAU**: monthly active users.
+- **WAU**: weekly active users. 
 
 ### Why should we enable Service Ping?