When is it necessary to have Header unset Vary in .htaccess

1. What does the vary header do?
2. How do I remove a Vary header?
3. What is vary user agent?
4. How do I add a header to an htaccess file?
5. What is vary accept-Encoding header?
6. What does vary origin mean?
7. Which of the following are allowed values for the content type in CORS requests?
8. What is content encoding GZIP?
9. What is HTTP origin?
10. How do you do dynamic servings?
11. How is dynamic serving implemented?

What does the vary header do?

The Vary HTTP response header determines how to match future request headers to decide whether a cached response can be used rather than requesting a fresh one from the origin server. ... The Vary header should be set on a 304 Not Modified response exactly like it would have been set on an equivalent 200 OK response.

How do I remove a Vary header?

Select the Remove Vary Header behavior, and click the Insert Behavior button. Set the Remove Vary Header slider to "Off".

What is vary user agent?

The Role of Vary: User-Agent

It tells Dynamic caching which version of your page should be served depending on the browser type, which can prevent a cached desktop version being served to a mobile visitor.

How do I add a header to an htaccess file?

Add Custom HTTP Headers with . htaccess

1. Hello, custom header. In this tutorial, we're talking about custom HTTP headers, which look like this: ...
2. The basic idea. To add a custom header, we use Apache's versatile Header directive, like so: Header add Custom-Header "parameter=value" ...
3. Server request & response. ...
4. Copy/paste examples. ...
5. Copy/paste examples. ...
6. Learn more..

What is vary accept-Encoding header?

What Does “Specify a Vary: Accept-Encoding Header” Actually Mean? Accept-encoding header is an HTTP header which must be included on every origin server response. Its main job is to inform the browsers if the client can handle the compressed version of the website.

What does vary origin mean?

Vary: Origin

When a user agent receives a response to a non-CORS request for that resource (for example, as the result of a navigation request), the response will lack `Access-Control-Allow-Origin` and the user agent will cache that response.

Which of the following are allowed values for the content type in CORS requests?

The only allowed values for the Content-Type header are: application/x-www-form-urlencoded. multipart/form-data. text/plain.

What is content encoding GZIP?

Accept-Encoding: gzip, deflate. The server responds with the scheme used, indicated by the Content-Encoding response header. Content-Encoding: gzip. Note that the server is not obligated to use any compression method. Compression highly depends on server settings and used server modules.

What is HTTP origin?

The Origin request header indicates where a request originates from. It doesn't include any path information. It is similar to the Referer header, but, unlike that header, it doesn't disclose the whole path.

How do you do dynamic servings?

In this situation, the server looks for the User Agent value in the HTTP header to determine whether it is dealing with a desktop, tablet, or smart phone. The server then sends out different HTML, CSS and JS code and media files (images, video, etc.) depending on the User Agent value.

How is dynamic serving implemented?

Option 2: Dynamic Serving

One way to implement dynamic serving is unidirectional redirecting, in which links to a site default to the desktop site, but mobile devices get redirected from the desktop site to the mobile site.