When you validate a page with 50 or 100 images -- and none of them use the alt attribute -- this can be a huge headache.

如果验证的页面有50或 100张图片，而且都没有使用alt属性，这可能是件很麻烦的事。

youdao

It is used in the ALT attribute of the HTML tag when the channel is rendered in HTML.

当频道以HTML呈现时，用作HTML标签的alt属性。

youdao

Longdesc is used to give a URI that points to a fuller description of the image than given in the Alt attribute.

longdesc用于提供一个URI，该URI指向关于图片的、与al t属性中的说明相比更详细的描述。

youdao

Longdesc is used to give a URI that points to a fuller description of the image than given in the Alt attribute.

longdesc用于提供一个URI，该URI指向关于图片的、与al t属性中的说明相比更详细的描述。

youdao