SGML Declaration

Hello,


i have strange situation...
Last day i check-up validation of my source. But not in validator.w3.com...Some validator (forgot name) and this validator scream STRANGE error:
Important: The special SGML declaration and DOCTYPE declaration below are needed for the good practice checking.
And i dig in NET for SGML declaration uncover this:

http://www.utoronto.ca/webdocs/HTMLdocs/HTML_Spec/xhtml1.0/xhtml1.dcl
(look this URL - 200 line shit)

My question is:
must i have this declaration? for what is this declaration and no matter put this declaration in my source will i have advantage?

Quote from: Kristalin at Aug 02, 2007, 06:10 AM

[...]
My question is:
must i have this declaration? for what is this declaration and no matter put this declaration in my source will i have advantage?

No i am quite sure it wouldn’t server any purpose if you did. I suppose those or similar definitions are also in the official w3c dtd definition files. It would be rather a waste if every website on the web would have to repeat it in full.

PS: I can’t check right now because the w3c.org server seems to have trouble serving pages al la

"Directory Listing Denied
This Virtual Directory does not allow contents to be listed."

very strange ..