diff --git a/devtools/client/locales/en-US/netmonitor.properties b/devtools/client/locales/en-US/netmonitor.properties
index 2ea416a4a48e..f2d4492ebae7 100644
--- a/devtools/client/locales/en-US/netmonitor.properties
+++ b/devtools/client/locales/en-US/netmonitor.properties
@@ -330,15 +330,16 @@ netmonitor.timings.requestTiming=Request Timing
 netmonitor.timings.serverTiming=Server Timing
 
 # LOCALIZATION NOTE (netmonitor.timings.queuedAt): This is relative queued time to the
-# first request
+# first request. %S is time expressed in milliseconds or minutes.
 netmonitor.timings.queuedAt=Queued: %S
 
-# LOCALIZATION NOTE (netmonitor.timings.startedAt): Related to first request,
-# when the request actually started
+# LOCALIZATION NOTE (netmonitor.timings.startedAt): Relative to the first request,
+# when the request actually started. %S is time expressed in milliseconds or minutes.
 netmonitor.timings.startedAt=Started: %S
 
-# LOCALIZATION NOTE (netmonitor.timings.downloadedAt): Related to first request,
-# when the request actually finished downloading
+# LOCALIZATION NOTE (netmonitor.timings.downloadedAt): Relative to first request,
+# when the request actually finished downloading.
+# %S is time expressed in milliseconds or minutes.
 netmonitor.timings.downloadedAt=Downloaded: %S
 
 # LOCALIZATION NOTE (networkMenu.millisecond): This is the label displayed