Why a keyword "strong" is used on a property in non-ARC environment?

I just started to develop with with Xcode 4.2 and iOS5. After creating empty Tabbed application project, I have noticed that a new keyword "strong" is used on properties. I re开发者_如何转开发ad on this post about it being related to retain replacement in ARC environment, but it's not the case because I didn't checked "Use Automatic Reference Counting" check box.

The keyword "Strong" is a synonym for "retain" in non-ARC environments.

For ARC-envs read up here: http://clang.llvm.org/docs/AutomaticReferenceCounting.html#ownership.spelling.property