Xoc - 8:12 pm on Apr 20, 2001 (gmt 0)

Well, I was going to say no, then I changed my mind to yes, then I changed it back to no again! I think it's okay. You can copy one of the w3c DTDs and modify it for your needs. I did this in one case because I wanted to validate the entire web site, but there was one automatically generated file that I didn't have complete control over the HTML, which was a mess. So I created a DTD and stuck the DOCTYPE at the beginning of the HTML file. That worked, more or less. The WDG validating spider ([htmlhelp.org ]) takes forever to run if even one file on the site doesn't validate.

My one caveat is that I can imagine a possibility that a browser might do something unexpected if it sees an unknown DOCTYPE at the beginning.