Indicates whether a user or user group already exists.
(Users and user groups share the same namespace, so both are tested.)
This does not require authorisation, because it can be called when there is no user.
However, it can be called with user credentials, these are just ignored.
If reference is not passed, then userExists and userGroupExists both return false.
In general, if a user exists, there will always be a matching user group, unless the user has been deleted in which case the user logon reference may still exist but the user group will not. The field referenceExists is therefore the best test for availability of a reference.
<errorNumber>0</errorNumber> <userExists>true|false</userExists> <userGroupExists>true|false</userGroupExists> <referenceExists>true|false</referenceExists>
referenceExists is set to true if either the user or user group exists.