Testing related realms Related realms is feature to provide login suggestion based on similar domains. Out of the scope of this feature is subdomain handling, which is already part of the base functionality. The intent is to cover the ebay.com/ebay.co.uk and all other country TLD cases where the sign in page is actually signin.ebay.com/signin.ebay.co.uk but credentials could have manually been entered for ebay.com/ebay.co.uk or automatically stored as signin.ebay.com/sigin.ebay.co.uk The related realms feature can be enabled via the preference signon.relatedRealms.enabled. It is disabled by default. This test proves that related logins show up in the autocomplete menu when the feature is enabled and that the related logins do not count as duplicates and therefore the form gets filled directly.