When creating a scan profile for Discovery in Credential Management, a list of servers is available for picking up in that Scan Profile.
However this list does not comprise- usually- all the servers defined in a PAM system
This article discusses what determines if a server will be visible in the list or not
CA PAM all releases
In order for a targetserver to be eligible as one of the servers in a Scan Profile it needs to have at least one targetaccount which has been marked as "Allow discovery" in the Password Tab of the account definition