It has been recently noted that the README_versioning_protocols.md section about Shard Version is not fully aligned with the current behavior of the source code - in particular:

• It defines a <E, T, M, m, I> tuple format for the Shard Version that does not match the <M, m, E, T> sequence of fields that is actually printed in log traces , complicating their interpretation;
• It still contains references the "Global Index Version" (removed by SERVER-104972 and related tasks).