<script type = "text / javascript + protovis"> what does the + sign mean?

Question

As the title says,

What does the + sign mean in <script type="text/javascript+protovis"> ?

Are there any good materials?

Answer 1

Shamelessly stolen from another answer here .

The template for naming mimetypes is as follows:

A point hierarchically separates several “elements” (for example, config is a child of iptv, that is, a child of nokia, that is, a child of VND).

The hyphen separates compound words (as in google-earth and openxmlformats-officedocument).

The plus sign serves to further indicate the serialization format (+ json and + xml in these examples).

The x prefix should be used for MIME types not registered with IANA (and thus not shown in this list).

In addition, text/javascript+protovis not equivalent to text/javascript . Two can be handled differently.