I suggest to add a new property to the NotesDatabase object to store version (application version eg.: 2.13.04 ) info. I think everybody used a "v.2.3" kind of extension in the title or in the About Document.
If a version property would be added to the database it can be checked from code or in the Administrator client or in the Catalog. It can be used as replication condítion also.
NotesDatabase.Version, 3 byte
SetMajorNumber to set the first digit
SetMinorNumber to set the second digit
SetMaintenanceNumber to set third digit
Present it in the Catalog, Administrator/Files tab, Property dialog, etc