diff --git a/default.yaml b/default.yaml
index c71cfd0a..3535c404 100644
--- a/default.yaml
+++ b/default.yaml
@@ -1007,10 +1007,12 @@ history:
     # in your country and the countries of your users.
     enabled: true
 
-    # how many channel-specific events (messages, joins, parts) should be tracked per channel?
+    # if the in-memory backend is enabled for a channel, how many channel-specific events
+    # (messages, joins, parts) should be retained?
     channel-length: 2048
 
-    # how many direct messages and notices should be tracked per user?
+    # if the in-memory backend is enabled for a user, how many direct messages
+    # and notices should be retained?
     client-length: 256
 
     # how long should we try to preserve messages?
diff --git a/traditional.yaml b/traditional.yaml
index bf44d60f..b9e52d92 100644
--- a/traditional.yaml
+++ b/traditional.yaml
@@ -978,10 +978,12 @@ history:
     # in your country and the countries of your users.
     enabled: true
 
-    # how many channel-specific events (messages, joins, parts) should be tracked per channel?
+    # if the in-memory backend is enabled for a channel, how many channel-specific events
+    # (messages, joins, parts) should be retained?
     channel-length: 2048
 
-    # how many direct messages and notices should be tracked per user?
+    # if the in-memory backend is enabled for a user, how many direct messages
+    # and notices should be retained?
     client-length: 256
 
     # how long should we try to preserve messages?