Is the name designed to be intentionally confusing?
I bet it's intended to be pronounced "Better Eff Ess."
> Chris: <Grin> Definitely both.
https://web.archive.org/web/20120627065427/http://www.linuxf...
> Btrfs (pronounced as "better F S", "butter F S", "b-tree F S", or simply by spelling it out)
and I heard all of them in practice (except for spelling it out). While you can hear the difference for "b-tree F S", the other ones are much harder to distinguish.