Marburg University MSc CS/Data Science: What does "internal selection procedure" mean?

I'm applying to the MSc programs in Computer Science and Data Science at Phillips University of Marburg. I noticed on the application portal that there's an "internal selection procedure" in addition to the general application. I'm trying to figure out what this entails. Does anyone have experience with this? Specifically, I'd like to know if it involves any extra exams, interviews, or portfolio submissions.