Implicity of web page structure in Schema.org
<p>After reading thousand of posts, questions, blog articles and opinions, I'm still a bit confused about how to markup a web page with microdata. If the main purpose of microdata is to help search engine to better understand the content of a web page (and web page is assumed implicitly), is it correct to start with itemtype Webpage in the body element, and then continue  to markup the rest of nested elements defining which is the main entity, or is it better to start with an itemtype that is ideally the main topic of the web page and associate properties at the top level, or is better to have different itemtype at the top level (i.e. webpage, blog post and main topic of the page)?</p>

<p>An example will explain better my question: if I have to markup a webpage that contains a blog post about a specific topic (let's say about wireless technology), what should be the item at the top level? Should be webpage, blogposting, or wireless technology?</p>