谷歌表示,不是为了向机器提供数据而隐藏信息,除非它是特定于机器的信息.为了提供这些数据,我找不到任何有关空元素的信息.

如果你看一下商业的GoodRelations RDFa生成器,你会得到一堆嵌套的div,你被告知放在你的项目页面的底部.我将使用我最喜欢的网站之一：

<div xmlns="http://www.w3.org/1999/xhtml"
  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-Syntax-ns#"
  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"
  xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
  xmlns:gr="http://purl.org/goodrelations/v1#"
  xmlns:foaf="http://xmlns.com/foaf/0.1/">

  <div typeof="gr:Offering" about="#offering">
    <div rev="gr:offers" resource="#company"></div>
    <div property="rdfs:label" content="Alpinestars S-MX Plus Racing Boots" xml:lang="en"></div>
    <div property="rdfs:comment" content="Alpinestars’ S-MX Plus racing boot raises performance and safety to new and unmatched levels with its innovative design,structural protection and comfort." xml:lang="en"></div>
    <div property="gr:hasEAN_UCC-13" content="0000000000000" datatype="xsd:string"></div>
    <div rel="foaf:depiction" resource="http://www.motorcycle-superstore.com/ProductImages/300/g17268.jpg"></div>
    <div rel="gr:hasBusinessFunction" resource="http://purl.org/goodrelations/v1#Sell"></div>
    <div rel="gr:hasPriceSpecification">
      <div typeof="gr:UnitPriceSpecification">
        <div property="gr:hasCurrency" content="USD" datatype="xsd:string"></div>
        <div property="gr:hasCurrencyValue" content="349.95" datatype="xsd:float"></div>
        <div property="gr:hasUnitOfMeasurement" content="C62" datatype="xsd:string"></div>
      </div>
    </div>
    <div rel="gr:acceptedPaymentMethods" resource="http://purl.org/goodrelations/v1#PayPal"></div>
    <div rel="gr:acceptedPaymentMethods" resource="http://purl.org/goodrelations/v1#AmericanExpress"></div>
    <div rel="gr:acceptedPaymentMethods" resource="http://purl.org/goodrelations/v1#Discover"></div>
    <div rel="gr:acceptedPaymentMethods" resource="http://purl.org/goodrelations/v1#MasterCard"></div>
    <div rel="gr:acceptedPaymentMethods" resource="http://purl.org/goodrelations/v1#VISA"></div>
    <div rel="foaf:page" resource="http://www.motorcycle-superstore.com/1/1/36/77/ITEM/Alpinestars-S-MX-Plus-Racing-Boots.aspx"></div>
  </div>
</div>

我觉得有趣的是它们的实现 – 百思买已经取得了巨大成功 – 是标签中没有实际内容,而只是内容属性.

那么我的问题是,是否有人对这种类型的实现有任何了解,以及使用一个利用content属性而不是将RDFa结构添加到现有标记的空div结构是否会受到惩罚？