Nesting h3 inside anchor - how is this valid?

Question

  
    
    
hello&         


        

Answer 1

If you look at the HTML5 spec, there is a section on the tag:

The a element may be wrapped around entire paragraphs, lists, tables, and so forth, even entire sections, so long as there is no interactive content within (e.g. buttons or other links).

I can't find anything in the HTML4 spec that says that putting block-level tags inside of inline-level tags is invalid, but I do remember reading it somewhere.