Technique SVR5:Specifying the default language in the HTTP header
About this Technique
This technique relates to 3.1.1: Language of Page (Advisory).
This technique applies to server-side technologies, including server-side scripting languages and server configuration files for setting HTTP headers.
Description
The objective of this technique is to provide information on the primary language or languages in a Web page, in order to identify the audience of the content. The Content-Language
HTTP header can contain a list of one or more language codes, which can be used for language negotiation between a user agent and a server. If the language preferences in a user agent are set correctly, language negotiation can help the user to find a language version of the content that suits their preferences.
Note that the Content-Language HTTP header does not serve to identify the language used for processing the content. The content processing language can be identified by means of other techniques, such as the attributes lang
and xml:lang
in markup languages.
This technique ensures that the primary language of the document, as specified for example in the lang
or xml:lang
attribute, is listed in the Content-Language
HTTP header.
Examples
Example 1: Setting content language in Java Servlet and JSP
In Java Servlet or JavaServer Pages (JSP), developers can use response.setHeader("Content-Language", lang)
, in which "lang" stands for a language tag (for example, "en"
for English):
...
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
...
response.setHeader("Content-Language", "en");
PrintWriter out = response.getWriter();
...
}
Example 2: Setting content language in PHP
In PHP, developers can send a raw HTTP header with the header method. The following example sets the language to French:
<?php header('Content-language: fr'); ... ?>
Related Resources
No endorsement implied.
- W3C Internationalization FAQ: HTTP and meta for language information
- Declaring metadata about the language(s) of the intended audience in Authoring HTML: Language declarations - W3C Working Group Note 3 June 2014.
- RFC 9110, 8.5. Content-Language
- PHP header.
Tests
Procedure
- Use a Live HTTP Header viewer to find the value of the
Content-Language
header. - Check that this value matches the default language of the Web page.
Expected Results
- Step #2 is true.