diff --git a/handbook/troggle/scriptscurrent.html b/handbook/troggle/scriptscurrent.html
index d92f6c5da..890e56f93 100644
--- a/handbook/troggle/scriptscurrent.html
+++ b/handbook/troggle/scriptscurrent.html
@@ -102,9 +102,11 @@ Get this from GitHub <a href="https://github.com/mshinwell/gps2survex">https://g
 <p>Read the <a href="troggle/make-essentialsREADME.txt">README</a> file in :loser:/gpx/y.
 <p>Someone needs to document this and and make_svx.sh properly.
 
-<h4 id="surface">make_svx.sh</h4>
+<h4 id="surface">gpx2survex and make_svx.sh</h4>
 <p>In :loser:/gpx/
 <p>Regenerates the surface tracks as survex files from GPS .gpx files. Also requires the gpx2survex program.
+  <p>We use the OCAML program gpx2survex but we now also have a python equivalent gpx2survex.py which is used by make_svx2.sh This is part of the make_essentials generation process.
+<p>gpx2survex simplifies a track so that it is less voluminous.
   <p>For the reverse process we don't need a script. For svx-to-gps we can use <var>survexport</var>: Olly says [2022]: "you shouldn't need to mess around with undocumented scripts - since 2018, you can just do: 
     <var>survexport --entrances all.3d essentials.gpx</var>"
     <p>But that does rather rely on <var>all.3d</var> being properly generated, which  troggle does not currently do reliably and automatically.