federation or alliance information

[obor]

Hello everyone:

I would like to know if it's possible that in the HTTP headers could go information about the alliances that the user's IDP belongs to.
I want to know how to get the alliance information but in other way than checking the IDP info (that comes in the http headers) and accessing to the corresponding alliance metadata file to check what alliances this IDP belongs to.

Thank you in advance

Jose