Article ID: 304531 - Last Review: July 30, 2007 - Revision: 3.4

Legacy Opt-Out Cookie Strings That Are Supported by Internet Explorer 6

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This article was previously published under Q304531

SUMMARY

This article describes the special provision that is implemented by Internet Explorer 6 for legacy opt-out cookies. Internet Explorer 6 defines legacy cookies as cookies that were on your computer prior to installing Internet Explorer 6.

MORE INFORMATION

Internet Explorer 6 makes a special provision for opt-out legacy cookies. Often, when you opt out of an online service, an opt-out cookie is used by the Web service to facilitate this choice. The success of this transaction sometimes relies on the ability of the browser to send this cookie in both first-party and third-party contexts. However, with Internet Explorer 6, legacy cookies are leashed and are not sent in the third-party context. In response to this problem, Internet Explorer 6 does not leash cookies that contain any of the following name/value pairs:

ID=OPT_OUT
AA002=optout
id=OPT_OUT
CyberGlobalAnonymous=optout

Note that these name/value strings are case sensitive and space sensitive.

Web sites should upgrade their opt-out cookies to use this syntax to ensure that legacy opt-out cookies are effective in Internet Explorer 6. After Internet Explorer 6 is installed, new opt-out cookies are handled just like any other non-legacy cookie. This special provision does not affect non-legacy cookies (cookies that are set after Internet Explorer 6 is installed).

For developer information about the Privacy implementation in Internet Explorer 6, visit the following Microsoft Web site:

http://msdn2.microsoft.com/en-us/library/ms537342.aspx (http://msdn2.microsoft.com/en-us/library/ms537342.aspx)