List of HTTP header fields

https://en.wikipedia.org/wiki/List_of_HTTP_header_fields

Content-Type

The MIME type of the body of the request (used with POST and PUT requests)

Content-Type: application/x-www-form-urlencoded

                                                                                                                                             

常见 MIME type

Type application

application/json: JavaScript Object Notation JSON;

application/pdf: Portable Document Format, PDF has been in use for document exchange on the Internet since 1993;

application/xml: XML files; 

Type text

text/css: Cascading Style Sheets;

text/csv: Comma-separated values;

text/html: HTML;

text/javascript (Obsolete): JavaScript; 

text/xml: Extensible Markup Language; 

List of common media subtype prefixes

application/vnd.ms-excel: Microsoft Excel files