diff --git a/Patches.md b/Patches.md
index b387336..b39afef 100644
--- a/Patches.md
+++ b/Patches.md
@@ -1,12 +1,16 @@
 Please create a new ticket to track the issue unless your patch is a patch for an issue that is already ticketed.
 
-Then run the following darcs commands to generate a darcs patch file:
+Then run the following darcs commands to generate a darcs patch file named `WHAT.diff`:
 
 ```
   darcs record local/path/to/file(s)
-  darcs send -o patch.darcspatch
+  darcs send -o WHAT.diff
 ```
 
 And attach it to the ticket.
 
+Please use a filename like *.diff (instead of *.patch) so that Trac will let other
+developers view it without first requiring them to download it first. (Trac's content-type logic maps
+*.patch to some application/blahblah MIME type, and browsers won't think they know how to render it).
+
 If you don't have darcs or don't want to use it, just attach a normal old diff.