github/objective-c-conventions — pull request #26 by Jlawr3nc3 (2012-12-02 18:30:49+00:00)
Title: Constructor return type

Constructors should use `instancetype` instead of `id` as their return type because methods that do not begin with one of the checked keywords (`alloc`, `init`, `new`, etc) will not get the same stricter type checking.

See http://clang.llvm.org/docs/LanguageExtensions.html#objc_instancetype