This property was used as a overall check for the WebKit rendering engine and later that included Chrome as well. So the property is there for compatibility reasons - the check goes like this: $telerik.isSafari = $telerik.isSafari2 || $telerik.isSafari3 || $telerik.isSafari4 || $telerik.isChrome;
We can introduce a new property, for instance $telerik.isWebKit, but we still shouldn't change the way isSafari currently works.