Mark talks about how he implemented his Dive Into Mark Mobile Edition, and in doing so talks about XHTML Basic, which I co-edited. He’s mostly correct, but there are some points I’d like to respond to.
The “link” element has a extremely low conformance profile; all it means to support it is that you don’t fault when you discover it. Supporting “link” doesn’t mean you have to support CSS.
As for the list of elements which XHTML Basic left out, “b”, “i”, “center”, and “font” aren’t there because XHTML 1.0 – from which XHTML Basic builds - removed them in the “presentation belongs in stylesheets” blitz of 1999. Nested tables were indeed removed based on extensive feedback and wide industry support for doing so, due to the memory consumed during their processing. Though I don’t know for sure, I’m quite confident that AvantGo does not support arbitrarily complex nested tables, which suggests that some form of subset would need to be defined should their solution ever be opened up anyhow.
It is not true that XHTML Basic has to use the application/xhtml+xml media type. In many cases it is appropriate to use “text/html”, though the W3C apparently disagrees with me there; their “XHTML Media Types” note says that it “SHOULD NOT” be used. Whatever. I doubt any text/html processor would have trouble with XHTML Basic, just don’t expect it to be treated as XML or XHTML.
Mark’s conclusion, “As I said, XHTML Basic has no basis in reality. Ignore it.”, for North Americans, probably isn’t too far from the truth. In much of Asia and parts of Europe though, it’s important, and its importance will probably be spreading.
Not that I really care that much. The reason I contributed to its development was because of Sun’s objective that WAP should use commodity protocols rather than wireless specific ones, and we did that. Though WAP 2.0 extended XHTML Basic, I’m confident that in time, those extensions will be ignored and HTML/XHTML will remain in some form, likely richer than XHTML Basic. I look forward to seeing that language documented after the fact; XHTML Basic 3.2 anyone? 8-)