rails/rails — pull request #7835 by jarl-dk (2012-10-03 19:33:37+00:00)
Title: Added :prefix => :iec option

This will use base 1024 and the notation (KiB, MiB, GiB, etc.)

http://en.wikipedia.org/wiki/Binary_prefix

Also corrected the SI prefix for thousands, SI states small-letter "k"
not kapital letter "K"