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the "id" of the IdPAttribute, which identifies the data inside the IdP
the naming of the object outside the IdP, as in the case of a SAML 2.0 Attribute's Name and NameFormat
the AttributeTranscoder that should be used to encode and decode the data values
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The "transcoder" property is referring to the bean names of the objects to use, which are documented on the parent page, and the others are pretty self-explanatory if you've seen defaults in older versions of Shibboleth. Note that as with all historical Shibboleth practice in the IdP and SP, that rule implies a SAML 2.0 NameFormat of “urn:oasis:names:tc:SAML:2.0:attrname-format:uri” and a SAML 1.1 AttributeNamespace of “urn:mace:shibboleth:1.0:attributeNamespace:uri”.
A complete explanation of how this works and what the property names are follows.
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