[RobinTW]

Other than that, as DaveBlake mentioned, you do have a remove facility, i.e. you can remove albums from the source, then this album will be removed from the library, by running the "clean library" process. Removing an album, but keep the files within the music source, just doesn't make sense. Create an other folder, name it Not-in-library or whatever you want, and move those albums out there what you don't want to see in the library, then run "clean library".

I think you do realize that you are communicating in a provocative, harsh style, what you do intentionally - this is not appreciated!

 I didn't mean to offend anyone.  If someone was offended, my apologies.
I am kinda old and what I learned back school for programming was Pascal and Fortran.  I really have no idea if adding "Remove" function is hard or not using current programming languages.
Sorry again.