anchor.diff:  %% @author Marc Worrell <marc@worrell.nl>
  -%% @copyright 2009 Marc Worrell
  +%% @copyright 2009-2012 Marc Worrell
   %% Date: 2009-04-17
   %%
   %% @doc Utility functions for html processing.  Also used for property filtering (by m_rsc_update).
   
  -%% Copyright 2009 Marc Worrell
  +%% Copyright 2009-2012 Marc Worrell
   %%
   %% Licensed under the Apache License, Version 2.0 (the "License");
   %% you may not use this file except in compliance with the License.
  
positive.code: allow_once(_) -> false.
  
  %% @doc Allowed elements (see also allow_once/1 above)
  allow_elt(<<"audio">>) -> true;
  allow_elt(<<"address">>) -> true;
  allow_elt(<<"bdo">>) -> true;
  
negative.code: allow_elt(_) -> false.
  
  %% @doc Allowed attributes
  allow_attr(Attr, Extra) ->
      allow_attr(Attr) orelse lists:member(Attr, Extra).
  
  allow_attr(<<"align">>) -> true;
  allow_attr(<<"alt">>) -> true;
  allow_attr(<<"autoplay">>) -> true;
  