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 ## About Rx
 
+**:warning: This readme describes RxSwift 3.0 version that requires Swift 3.0:warning:**
+
+**:warning: If you are looking for Swift 2.3 compatible version, please take a look at RxSwift ~> 2.0 versions and [swift-2.3](https://github.com/ReactiveX/RxSwift/tree/rxswift-2.0) branch :warning:**
+
 Rx is a [generic abstraction of computation](https://youtu.be/looJcaeboBY) expressed through `Observable<Element>` interface.
 
 This is a Swift version of [Rx](https://github.com/Reactive-Extensions/Rx.NET).