Can you help me to understand how Dassault is versioning this software?

Whenever I google it, It displays answers like "CATIA V5", "CATIA V5-6R2023," or "CATIA v6-3DX (3D Experience)"

However, my global support team refers to CATIA versions such as CATIA R34, CATIA R31, CATIA R30, etc.

I wanted to know what version to look for my users. They need the latest read-only version; they don't modify the files, just review them.