From Facebook Developer Wiki

Description

Facebook will deprecate this tag in late 2009/early 2010.

You can integrate with the profile using application tabs. For more information, please read the Developer Roadmap.

Renders an Add to Profile or Add to Info button (depending upon which section attribute you specify) on an application's canvas page. This button allows a user to add either a new condensed profile box to the main profile or a new application info section to the Info tab.

Important: The button appears only if the application has already called profile.setInfo or profile.setFBML and set info for that user. We recommend you call profile.setInfo after the user has entered enough data for your application to be able to make a compelling info section.

If the user already has a condensed profile box or an info section from the application, the button does not appear on that application's canvas page.

The Platform Principles and Policies state that you cannot incentivize users to add integration points, so you cannot know whether the user has added a profile box. However, you can use the fb:if-section-not-added tag to have Facebook render contents -- such as the fb:add-section-button tag with an explanation for the user -- only if the user hasn't added the profile box or info section.

Attributes

Required	Name	Type	Description
required	section	Specifies whether to add a condensed profile box to the main profile (profile) or an application info section to the Info tab (info).

Examples