Notes provides new functionality in Lotus Script and there also Java classes added to the client.
Lotus Script Named documents have been introduced in Notes/Domino 12.0.1.
I have just written an application which needs a Java class which is introduced in Notes 12.0.2 as it turned out.
So I came up with a simple check I am going to add to all my applications which use more current functionality.
You can drop this code into the PostOpen script of any database and switch to the right constant
This is a companion discussion topic for the original entry at https://blog.nashcom.de/nashcomblog.nsf/dx/check-the-minimum-client-version-for-your-notes-application.htm