Documentation for Crowd 2.3. Documentation for other versions of Crowd is available too.
Enabling 'Allow immediate authentication requests' allows an OpenID-enabled site to check whether the user is logged in, without actually prompting the user to login. Known as pass-through authentication, this provides greater convenience for end-users, particularly when an end-user visits a site for which they have previously selected 'Allow Always' (see 2.4 Allowing or denying a login in the CrowdID User Guide).
To enable 'Allow immediate authentication requests',