If the original article link could not be detected either, the link to the alternate entry resource representation is given, as specified in the link element with rel attribute having alternate value.

如果初始文章链接也检测不到，就会给出到可选的条目资源表示的链接，正如在link元素中通过让rel属性的值为alternate所指定的那样。

youdao

Beware: while you can use multiple values in the media attribute, they must be separated by commas, as opposed to the Spaces you'd use for values of the rel attribute.

注意：虽然可以在media属性中使用多个值，但是这些值之间必须以逗号隔开，而不是像rel属性的值那样使用空格作为分隔符。

youdao

In contrast to RDFa, microformats reuse existing XHTML attributes that web content authors were already used to, such as the rel attribute on links.

与rdfa相比，微格式重用了Web内容作者已经习惯的现有xhtml属性，比如链接上的rel属性。

youdao