Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide

NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Get The TCP/IP Guide for your own computer.
The TCP/IP Guide

Custom Search

Table Of Contents  The TCP/IP Guide
 9  TCP/IP Application Layer Protocols, Services and Applications (OSI Layers 5, 6 and 7)
      9  TCP/IP Key Applications and Application Protocols
           9  TCP/IP File and Message Transfer Applications and Protocols (FTP, TFTP, Electronic Mail, USENET, HTTP/WWW, Gopher)
                9  TCP/IP World Wide Web (WWW, "The Web") and the Hypertext Transfer Protocol (HTTP)
                     9  TCP/IP Hypertext Transfer Protocol (HTTP)
                          9  HTTP Message Headers

Previous Topic/Section
HTTP General Headers
Previous Page
Pages in Current Topic/Section
Next Page
HTTP Response Headers
Next Topic/Section

HTTP Request Headers
(Page 1 of 4)

HTTP request headers, as you might imagine, are used only in HTTP request messages, and serve a number of functions in them. First, they allow the client to provide information about itself to the server. Second, they give additional details about the nature of the request that the client is making. Third, they allow the client to have greater control over how its request is processed and how (or even if) a response is returned by the server or intermediary.

This is the largest of the four categories of HTTP headers, comprising over a dozen different types.


Allows the client to tell the server what Internet media types it is willing to accept in a response. The header may list several different MIME media types and subtypes that the client knows how to deal with. Each may be prepended with a “quality value” (“q” parameter) to indicate the client's preference. If this header is not specified, the default is for the server to assume any media type may be sent to the client. See the topics on entity media types and content negotiation for more information on how this header is used.


Similar to Accept, but specifies what character sets the client is willing to accept in a response, rather than what media types. Again, the listed charsets may use a “q” value, and again, the default if the header is omitted is for the client to accept any character set.


Similar to Accept and Accept-Charset, but specifies what content encodings the client is willing to accept. This is often used to control whether or not the server may send content in compressed form. (Remember that content codings are not the same as transfer encodings.)


Similar to the preceding Accept-type headers, but provides a list of language tags that indicate what languages the client supports or expects the server to use in its response.

Previous Topic/Section
HTTP General Headers
Previous Page
Pages in Current Topic/Section
Next Page
HTTP Response Headers
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $

Home - Table Of Contents - Contact Us

The TCP/IP Guide (
Version 3.0 - Version Date: September 20, 2005

Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.