diff --git a/docs/UsersManual.html b/docs/UsersManual.html
index 130fcef..22d44ce 100644
--- a/docs/UsersManual.html
+++ b/docs/UsersManual.html
@@ -229,6 +229,9 @@
 
 <p>When this is disabled, Clang will print "test.c:28: warning..." with no
 column number.</p>
+
+<p>The printed column numbers count bytes from the beginning of the line; take
+care if your source contains multibyte characters.</p>
 </dd>
 
 <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
@@ -395,6 +398,9 @@
 </pre>
 
 <p>The {}'s are generated by -fdiagnostics-print-source-range-info.</p>
+
+<p>The printed column numbers count bytes from the beginning of the line; take
+care if your source contains multibyte characters.</p>
 </dd>
 
 <!-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -->
@@ -415,6 +421,9 @@
 &quot;\\&quot;), tabs (as &quot;\t&quot;), newlines (as &quot;\n&quot;), double
 quotes(as &quot;\&quot;&quot;) and non-printable characters (as octal
 &quot;\xxx&quot;).</p>
+
+<p>The printed column numbers count bytes from the beginning of the line; take
+care if your source contains multibyte characters.</p>
 </dd>
 
 <dt id="opt_fno-elide-type">