Microdata: HTML5’s Best-Kept Secret

Microdata: HTML5’s Best-Kept Secret

<div itemscope itemtype="http://data-vocabulary.org/Organization">
    <h1 itemprop="name">Hendershot's Coffee Bar</h1>
    <p itemprop="address" itemscope itemtype="http://data-vocabulary.org/Address">
      <span itemprop="street-address">1560 Oglethorpe Ave</span>,
      <span itemprop="locality">Athens</span>,
      <span itemprop="region">GA</span>.
    </p>
</div>

The Microdata markup adds a couple attributes you may not have seen before, itemscope, itemtype and itemprop. The first is essentially just a top level marker, it tells the search engine spider that you’re about to define something in the following nested tags. The itemtype attribute tells the spider what you’re defining — in this case, an organization.

The rest of the markup should look pretty familiar if you’ve used Microformats. The main change is the itemprop attribute (short for item property) to define what each element is. Because our address is all one paragraph, we’ve added some span tags to define each element of the address separately — street address, locality and so on. If we wanted, we could add other properties like a phone number (itemprop="tel"), a URL (itemprop="url") or even geodata (itemprop="geo").

So where did we get these itemprop vocabularies from? Well, as the URL in the itemtype attribute indicates, they come from data-vocabulary.org. Of course you can make up your own itemprop syntax, but if you want search engine spiders to understand your microdata, you’re going to have to document what you’re doing. Since the definitions at data-vocabulary.org cover a number of common use cases — events, organizations, people, products, recipes, reviews — it makes a good starting point.

Microformats and RDFa
Actually, the reasoning seems to have been something like this: Microformats are a really good idea, but essentially a hack. Because Microformats rely only on the class and rel attributes, writing parsers to read them is complicated.

At the same time, RDFa was designed to work with the now-defunct XHTML 2.0 spec. Although RDFa is being ported to work with HTML5, it can be overly complex for many use cases. RDFa is a bit like asking what time it is and having someone tell you how to build a watch. Yes, RDFa can do the same things HTML5 microdata and Microformats do (and more), but if the history of the web teaches us a lesson, it’s that simpler solutions almost always win.

google - 複合式摘要與結構化標記 - 網站管理員工具說明

* Using Microformats in HTML5
* Where on the Web Is HTML5?
* Add Semantic Value to Your Pages With HTML 5
* Microformats are Awesome, Now Put Them to Work for Your Site