recent Error: reference to non-SGML character occurrence

Just recently, my pages fail to validate <!doctype html public
"-//W3C//DTD HTML 4.01 Transitional//EN"> with an "Error: reference to
non-SGML character" for code such as &#151; (m-dash) &#133; (ellipses)
etc. and the message "Sorry, this document does not validate as HTML
4.01 Transitional." 
I can't find any links to further information. The numeric codes
previously validated (<meta http-equiv="Content-Type"
content="text/html; charset=utf-8"> and <meta http-equiv="Content-Type"
content="text/html; charset=ISO-8859-1"> both fail to validate, perhaps
I must use a different character set definition?). 
Is there a cure/work-around, or do I have to give up numeric character
entity references? I can't find many Character entity references for
these characters. The one source
(http://www.w3.org/TR/1999/REC-html401-19991224/sgml/entities.html)
implies &mdash; or &#8212; can be used instead of &#151;, but I wonder
how older browsers will handle this. And there is no mention of
ellipses.
Any advice would be appreciated.
Stan Hutchings

Received on Monday, 24 September 2001 19:25:53 UTC