diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index 8c8108f..a189f5f 100644
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -15,6 +15,10 @@ services:
         max-size:            "200k"
         max-file:            "20"
 
+  # Databases in use:
+  # 0: Flask Cache
+  # 1: Celery (backend)
+  # 2: Celery (broker)
   redis:
     image:                   redis:3.2.8
     container_name:          redis