[PaulHoule]

The HTML 5 spec says exactly how you're supposed to deal with broken HTML files.

[nukem222]

Yes, that is a single spec with correspondingly-small importance. Generally parsing html remains extremely difficult.

[kibwen]

It's of quite large importance, and despite being difficult, it is well-specified, which is the point here. Importantly, there is also no competing HTML spec, either de facto or otherwise. CSV doesn't have anything of comparable authority.