Broadly, I'd say there are three categories, in ascending order of change difficulty: 1. Private code. Renaming things is easy, since you only have to worry ab

Broadly, I'd say there are three categories, in ascending order of change difficulty: 1. Private code. Renaming things is easy, since you only have to worry about your own references. 2. Libraries with no external dependencies. Changing symbols in the public API can break clients, but clients can always not upgrade and everything will continue working exactly as before. 3. Libraries with external dependencies, like on an operating system (e.g. UIKit) or a web service. Changing names will break clients that don't also upgrade. IMO this doesn't really count as changing the name in code, per se — the issue isn't that the downstream code is coupled to the library code, per se, but the underlying infrastructure.