"the HTML spec" is definitely not the same as "HTML in the wild", so your comment has relatively little to do with what the parent comment is saying. Real web p

"the HTML spec" is definitely not the same as "HTML in the wild", so your comment has relatively little to do with what the parent comment is saying. Real web pages contain all sorts of sins (or at least did, back in the 90's) such as unclosed tags and missing elements that are "required", and browsers were expected to parse those pages because other browsers did. As a simple example, <b><i>foo</b></i> is not valid HTML 4 (or even SGML) because the tags are not strictly nested, but it would be suicide to make a browser that rejects pages containing that.