There are elements which are easily identifiable but still not classified by BluAge and coming as Unknown?Why?

Control Cards and Copybooks cannot be identified if they are not used by other programs, i.e. JCL and Cobol. This is mainly because they don't contain enough syntaxic information to let Blu Insights be sure at 100% of their types. Manage Types can help to do it within a few click. See the documentation for more details.

Please find documentation on classification here :

https://bluinsights.aws/blog/Self-Service-Classification

https://bluinsights.aws/docs/codebase-classification-manage-types