[idoubtit]

This a very verbose and confuse article. Mixing P/LI and IMG/BR is wrong. I think the situation could be explained with two points:

1. The autoclose syntax does not exist in HTML5, and a trailing slash after a tag is always ignored. It's therefore recommended to avoid this syntax. I.e write <br> instead of <br />. For details and a list of void elements, see https://developer.mozilla.org/en-US/docs/Glossary/Void_eleme...

2. It's not mandatory to close tags when the parser can guess where they end. E.g. a paragraph cannot contain any line-block, so <p>a<div>b</div> is the same as <p>a</p><div>b</div>. It depends on the context, but putting an explicit end tag is usually less error-prone.

[vbezhenar]

Putting an explicit end tag is more error-prone. It won't do anything for valid HTML but it'll add empty tag for invalid HTML. If you want to improve human readability, put end tag enclosed in HTML comment. At least it won't add empty elements.