From: "Y. NOBUOKA" Date: 2011-04-24T20:30:41+09:00 Subject: Re: Does String#encode in Ruby 1.9.2 have option :fallback? Hi, You can use :fallback option on ruby 1.9.2. I think you must not set :undef option when you use :fallback option. # example on ruby 1.9.2p180 # U+3042 is a Japanese character, and it cant express in US-ASCII "\u3042".encode( Encoding::US_ASCII, fallback: { "\u3042" => 'a' } ) #=> "a" -- NOBUOKA Yu