This question as already asked for RQM 4
https://jazz.net/forum/questions/82054/rqm-4-can-i-delete-test-plan-environments-to-simplify-platform-coverage?redirect=%2Fforum%2Fquestions%2F82054%2Frqm-4-can-i-delete-test-plan-environments-to-simplify-platform-coverage
Is the answer still valid for RQM 6, or did anything change?

My problem:
In the "Manage Project Properties" / "Test Environment Types" settings I have the following pre-defined values: CPU, Installed Software, Operating System, Remote Connection. They cannot be removed.

Besides these there are pre-defined Lab Resources, such as (including hidden ones): IP Interface, L2 Interface, Machine, Software Patch, Version, Virtual Image.

However when creating a TCER with "Generate Test Environments" I see the following types: Browsers, Test Adapter, Database, Application Server, Management Agent.
Where do these types come from? Where can I delete / hide them?

Thanks for your answers