4. Metadata Considerations

The Embedded Discovery Service (EDS) gets the information it displays from SAML metadata. The EDS prefers to pull information from the Metadata Extensions for Login and Discovery, often referred to as the mdui extensions. These extensions contain display names, descriptions, logos, and so forth. This page gives recommendations to identity providers regarding the proper use of the mdui extension elements.

The Metadata Extensions for Login and Discovery specification is relatively new and therefore many metadata feeds will not yet contain this information. The current Centralized Discovery Service (version?) uses the <md:OrganizationDisplayName> element within the SAML metadata and so many federations will have this populated already. If the legacyOrgNames option is used, then in cases where the UI extensions are not available, the <md:OrganizationDisplayName> elements will be used by the EDS as well.

The <mdui:DisplayName> elements for the IdPs must be localized. Equally, the EDS will be localized. It is therefore important to choose a defaultLanguage for the EDS that will allow the IdP names to be rendered properly. See here for more information.

Recommendations for metadata extensions

IdPs following the recommendations below will give their users the best experience at the EDS.

Federations are encouraged to pass these recommendations on to their customers, as well as the recommendations for SPs and any recommendations for their own Centralized Discovery Service.


Text should be provided in all appropriate languages. Federations should make detailed recommendations.


The EDS makes best effort to work with all supplied logos and will "chose the best fit". However properly sized logos will render well. Specifically:

  • The URL specifying the logo must be https protected.

  • One logo should be provided of size approximately 80px (width) by 60px (height). A larger logo may be provided but the aspect ratio should be maintained (logos are selected based on aspect ratio).

  • One logo should be provided of size 16px by 16px.

  • Logo backgrounds should be transparent.


The EDS uses the <DisplayName>. Federations may choose to make recommendations about this. Overly long DisplayNames are truncated (by default at 33 characters).


In the future the EDS may use <Description> (in alt text).


The EDS does consult the <Keywords> element when performing a search. Federations should be aware of this when making recommendations.

Other Elements

The EDS does not currently consult any other elements of the mdui extension set. However, federations may choose to make recommendations about other elements as future versions of discovery may take advantage of them.