还在试验当中或者非官方的MIME类型在二级分类开头会加一个“x- ”。

Experimental, or unofficial MIME types are denoted with a subtype that starts with, "x -".

youdao

还在试验当中或者非官方的MIME类型在二级分类开头会加一个“x- ”。

Experimental, or unofficial MIME types are denoted with a subtype that starts with, "x -".

youdao