diff --git a/lib/autocorrect b/lib/autocorrect
index 41131e2564..c8f9b2cf33 100644
--- a/lib/autocorrect
+++ b/lib/autocorrect
@@ -4,7 +4,8 @@
 # from TeXMacs (they give vdhoeven@texmacs.org as contact)
 #
 # We do it a bit differently and allow corrections only to combine a symbol
-# and a char to a new symbol.
+# and a char to a new symbol. In other words the combination of the first column
+# followed by the second column produces third column in the mathed.
 #
 #