[nomsternom]

It's also a processing instruction rather than an element, which makes it possible to put it inside e.g. a <table> element and partially replace some rows.

[mgr86]

I think semantically this is the perfect choice. Considering the history and intended use of PI.

As an aside, I’m still rather annoyed that web components use hyphens. I really thought colon’s and namespaces made perfect sense there.