module ActiveSupport::Multibyte::Unicode

def normalize(string, form=nil)

Default is ActiveSupport::Multibyte.default_normalization_form.
the following: :c, :kc, :d, or :kd.
* form - The form you want to normalize in. Should be one of
* string - The string to perform normalization on.

and validations.
considered the best normalization form for passing strings to databases
Returns the KC normalization of the string by default. NFKC is 
def normalize(string, form=nil)
  form ||= @default_normalization_form
  # See http://www.unicode.org/reports/tr15, Table 1
  codepoints = string.codepoints.to_a
  case form
    when :d
      reorder_characters(decompose(:canonical, codepoints))
    when :c
      compose(reorder_characters(decompose(:canonical, codepoints)))
    when :kd
      reorder_characters(decompose(:compatibility, codepoints))
    when :kc
      compose(reorder_characters(decompose(:compatibility, codepoints)))
    else
      raise ArgumentError, "#{form} is not a valid normalization variant", caller
  end.pack('U*')
end