Regarding the Priority property of NotesReplication (in LotusScript) and Replication (in Java), the settings DB_REPLICATION_PRIORITY_NOTSET (LotusScript) and CNOTES_REPLCONST_PRIORITYNOTSET (Java) are not supported as of R5.0.1.
Setting this value causes a run-time error. In normal usage, you cannot get this value with these properties.