could someone tell me how to add an explicit policy to register a user?

If you don't have an organizational policy you have to use an explicit one
if you like to use the Lotus Notes ID-Vault feature.

The attribute "IDVault-database" is set in a subcriber rule.

I tried already to add a destination attribute named "Policy" with the name
of the policy.
If I check the persons document in Lotus the policy is set. But the ID-Vault
is empty.
If I register a user by the Lotus Client and configure to use the policy
everythings works fine.

Therefore the error must be on the IdentityManagers site.

I tried also the "notes-policy-name" attribute. But that's also not the