Digital interoperability: Vocoders, Standards, Oh My!

I have been trying to figure out which digital radios can communicate with each other using digital voice. I have come across a lot of terms and acronyms and I am trying to sort out which is a standard and which is a vocoder. My goal is to try and put together a list of digital radios that can interoperate between each other.



Question #1: Does a list such as this already exist?



Questions #2: What part of radio specifications do you need to look in order to determine if a radio is interoperable with another.



Questions #3: Do I have these terms below grouped properly? Are there any I have missed?



Standards



1. DMR

2. P25

3. NXDN

4. MotoTRBO

5. D-Star

6. dPMR



Vocoders



1. AMBE+2C (Advanced Multi-Band Excitation)

2. IMBE (Improved Multi-Band Excitation)



Thank you!



P.S. I do realize that analog is the ultimate interoperable feature, however I am trying to find out which digital radios will work with each other.