What is "queuedFileVersions" ? Is it bad to have a large number? What does it mean?

I have a powershell script provided by support that generates a nice HTML report. I have it run daily. I'm wondering what this particular field, queuedFileVersions, means. Also,  QueuedRPFSFiles and QueuedRPFSSize. What's the optimal number? What do they mean? Is it useful to monitor these fields, and see how backed-up or queued-up a repository is?

Google / this KB has little to no info about what these fields mean.

QueuedRPFSfiles QueuedFileVersions QueuedRPFSSize