One of the reasons I’ve avoided using the XHTML 1.0 Strict DOCTYPE is that it doesn’t include the target attribute, which I use occasionally to open outside sites in a new window. It’s possible to do the same thing with JavaScript, but JavaScript may be turned off by your visitors for any number of reasons. What to do?
XHTML modularization to the rescue! Accessify.com has instructions on how to put together your own custom XHTML 1.1 Strict DOCTYPE, pulling in the XHTML module that allows you to use target and still validate. Slick!
NOTE: There are good reasons to just stick with the transitional DOCTYPE for now, mostly having to do with the way JavaScript operates in an XML environment vs. an HTML environment and with the known difficulties of properly serving strict XHTML using the application/xhtml+xml MIME type. Mark Pilgrim has written an excellent article for XML.com covering both issues. He’s also written a compelling weblog entry detailing a scenario in which the combination of strict XHTML, intolerant parsers, and invalid trackbacks and comments could cause a web site meltdown.
I’m looking forward to the day when such issues are resolved, so that this technology can get out of limbo and onto the web. Don Park has a good idea of how to do this with his “biased liberal” approach to XML parsing. I don’t expect such common sense to take hold any time soon, however, and from Don’s follow-up posts it sure doesn’t look promising. My guess is that either users will have to scream for this feature — or Microsoft will have to implement it first — before we see it catch on elsewhere.