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Requested attributes in SP metadata are sometimes used by the IdP to make runtime decisions with respect to attribute release. Along with other user interface elements, requested attributes are also used to construct the user consent page at the IdP (if one exists). It is recommended that all SP metadata contain the SP's required and optional attributes, a described in this document.
At runtime, requested attributes may be presented to the user on the consent page. The user will be asked whether or not the requested attributes should be released to the SP, so care should be taken to request only those attributes actually needed by the service.
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