Names You Can’t Use (aka reserved words, keywords) from Ruby and RubyOnRails ADDITIONAL_LOAD_PATHS ARGF ARGV ActionController ActionView ActiveRecord ArgumentError Array BasicSocket Benchmark Bignum Binding CGI CGIMethods CROSS_COMPILING Class ClassInheritableAttributes Comparable ConditionVariable Config Continuation DRb DRbIdConv DRbObject DRbUndumped Data Date DateTime Delegater Delegator Diges