diff --git a/documentation/users b/documentation/users
index 45aa89a..030d339 100644
--- a/documentation/users
+++ b/documentation/users
@@ -65,6 +65,16 @@ Create a new repository with the suffix ".mlist":
 CLIF will then begin accepting emails for project@example.org and store them
 inside the "project.mlist" repository.
 
+# Subscribe to a list
+
+Send an email to the list address with the +subscribe suffix. For example
+username/reponame+subscribe@example.org
+
+# Unsubscribe from a list
+
+Send an email to the list address with the +unsubscribe suffix. For example
+username/reponame+unsubscribe@example.org
+
 # New threads
 
 New threads are created simply by sending a new email to the list address. An account