alexandre@(none):~$ irb
irb(main):001:0> puts "STéPHANIE"
STéPHANIE
=> nil
irb(main):002:0> puts "STéPHANIE".gsub(/é/,"E")
STEPHANIE
=> nil
irb(main):003:0> puts "STéPHANIE".gsub(/[ÉÈÊËéèêë]/, "E")
STEEPHANIE
=> nil
irb(main):004:0>