diff --git a/handbook/survey/newcave.html b/handbook/survey/newcave.html
index 117e628cb..e3940d457 100644
--- a/handbook/survey/newcave.html
+++ b/handbook/survey/newcave.html
@@ -119,8 +119,11 @@ for the <a href="onlinewallet.html">online wallet maintenance process</a> ].
 
 <p>If your initial backup photos of your notes were poor quality, use the 
 scanner in the potato hut to make better copies. Scan to JPEG format as .jpg files.
-<p>Name the scanned pages "<em>notes1.jpg</em>, <em>notes2.jpg</em>" etc. This is important as a script detects whether these files exist
-and if you name them something else it will hassle you unnecessarily.
+<p>Name the scanned pages "<em>notes-1.jpg</em>, or perferably <em>notes-cavepassagename.jpg</em>" etc. This is important as a script detects whether these files exist
+(with names beginning "notes.." and "elev..") and if you name them something else it will hassle you unnecessarily.
+
+<p>[ Note to maintainers: do not rename these files even if they have been created with the wrong names. 
+They are permanently referred to by the tunnel/therion/troggle system !]
 
 <p>Scanned survey notes are voluminous and so are not kept in the version control system. Instead it is all kept
 in the file bucket "expofiles" on the expo server in Cambridge.