HTML block types 6 and 7

For type 6, there are a number of HTML elements listed specifically. Why only those elements?

But why does type 6 even exist? Why isn’t type 7 (assuming it were changed to have 6’s end condition) sufficient?

You need case 6 for things like


Case 7 only gets you


That doesn’t answer the first part of the question: why those tags for case 6? Why not just allow any tag for case 6 as well?

Because we don’t want, for example,


to be a raw HTML block. (This is, rather, a paragraph with some inline HTML content.)