Isn't this functionality a part of what toc needs and does? Then probably the toc plugin's code could be split into the part that implements the ?headinganchors's functionality and the TOC generation itself. That will bring more order into the code and the set of available plugins. --Ivan Z.

A patch to make it more like MediaWiki:

--- headinganchors.pm
+++ headinganchors.pm
@@ -5,6 +5,7 @@
 use warnings;
 use strict;
 use IkiWiki 2.00;
+use URI::Escape;

 sub import {
         hook(type => "sanitize", id => "headinganchors", call => \&headinganchors);
@@ -14,9 +15,11 @@
         my $str = shift;
         $str =~ s/^\s+//;
         $str =~ s/\s+$//;
-        $str = lc($str);
-        $str =~ s/[&\?"\'\.,\(\)!]//mig;
-        $str =~ s/[^a-z]/_/mig;
+        $str =~ s/\s/_/g;
+        $str =~ s/"//g;
+        $str =~ s/^[^a-zA-Z]/z-/; # must start with an alphabetical character
+        $str = uri_escape_utf8($str);
+        $str =~ s/%/./g;
         return $str;
 }
 

--Changaco