This marks the beginning of an AuthBy clause in a Handler or Realm, which defines how to authenticate and record accounting information for all the users in this Realm or Handler. The xxxxxx is the name of a specific AuthBy module. For more information about configuring specific AuthBy clauses, see the relevant sections.

You can have 0 or more AuthBy clauses in a Handler or Realm. The AuthBy clauses will be executed in order until the AuthByPolicy for the Realm or Handler is satisfied.

<AuthBy xxxxxx> both defines an authentication method and specifies where it should be used.

Note that something like

<Realm xxxxxx>
      <AuthBy xxxxxx>
            ....
      </AuthBy>
      ....
</Realm>

Is equivalent to

<AuthBy xxxxxx>
      Identifier myidentifier
      .....
</AuthBy>
<Realm xxxxxx>
      # This authenticates through the AuthBy defined above
      AuthBy myidentifier
      ....
</Realm>