On command clickng the window title: this feature has been around since classic Mac OS (I believe, it had been introduced in one of the many iterations of Syste

On command clickng the window title: this feature has been around since classic Mac OS (I believe, it had been introduced in one of the many iterations of System 7) – there was definitely no indicator or hint. But the functionality was about the same as the location drop-down at top center of the file dialogs and was anchored in about the same position. It may have been one of the first hidden features, apart from the easter egg in the Finder's about box.