Issue #5196 has been updated by Tomoki Imai . Thank you for informations. But why there is TRUE? irb(main):007:0> TRUE = false (irb):7: warning: already initialized constant TRUE => false TRUE can be update. So,There is no reasons why I use TRUE. And,I think,there is no reasons why true is not True. With capitalized True,we can manifest "You can't update True!" ---------------------------------------- Bug #5196: true should be True. http://redmine.ruby-lang.org/issues/5196 Author: Tomoki Imai Status: Open Priority: Normal Assignee: Category: core Target version: ruby -v: ruby 1.8.7 (2011-06-30 patchlevel 352) [x86_64-linux] Hello.I'm Tomoki Imai. I found Ruby has inconsistency. true is constant value. In irb, true = nil (irb):5: Can't assign to true true = nil ^ from (irb):5 from :0 We can't change value true. In Ruby,we use capitalized name for constant value. For example, A = 3 . This is why true should be True. -- http://redmine.ruby-lang.org