diff --git a/html/generation_doc.m b/html/generation_doc.m
index 18fba70518c89d37624900702cb0ef65d1a49723..f7dd6973f6a7a37db1425f8ab3317d6bbb47ead7 100644
--- a/html/generation_doc.m
+++ b/html/generation_doc.m
@@ -1,3 +1,7 @@
+%% Regenerate documentation
+% This file regenerates documentation in the current directory.  It only
+% works on files starting with 'TT_', and does not recurse.  It also
+% doesn't evaluate code.
 files = dir
 c = 0
 for i = 1:length(files)