Problem with validator: Invalid page at W3C

From: Martin J. Duerst (
Date: Sun, Aug 22 1999

Date: Sun, 22 Aug 1999 23:13:03 -0400 (EDT)
Message-Id: <>
From: "Martin J. Duerst" <>
Subject: Problem with validator: Invalid page at W3C

I got the following mail:

> The page at
> starts with this:
> <H1>
>   W3C&#153; Copyright Document Notice and License
> </H1>
> This "&#153;" is invalid and should be either "&#8482;", "&#x2122;" or
> "&trade".

Checking this with the validator
I got

 No errors found!

This is definitely wrong. Please note that
  Character encoding: iso-8859-1 
     Warning: the character encoding specified in the HTTP header (iso-8859-1)
     is different from the one specified in the META element (windows-1252). I
     will use iso-8859-1 for this validation.
does not affect the fact that it is wrong; if there were a byte value
corresponding to 153, it would be okay as windows-1252, but &#153; is
not allowed in any HTML document.
The syntax "&#D;", where D is a decimal number, refers to the Unicode
decimal character number D.
(there is no character number 153 in Unicode!)

This seems to point to a problem in the validator. It looks like
the invocation of nsgmls should be changed, or the version of nsgmls,
or there is a problem in nsgmls itself.

If I can help in any way to correct this problem, please tell me.

Regards,   Martin.

#-#-#  Martin J. Du"rst, World Wide Web Consortium