I vaguely remember a trick from years ago that I'd find useful now. I'm wondering if anyone remembers the details. (I'm assuming this is no longer possible so no longer a "can this be done now" question.)
I have a new 2018 Mac Mini to configure as a headless server. The typical way to do this is to attach a keyboard/mouse/monitor, then configure Remote Management, then disconnect the keyboard/mouse/monitor and reboot.
I'm reasonably certain there was once a method to configure a new (unconfigured) headless Mac 100% remotely. I think you'd boot it on a LAN, find the DHCP-assigned IP address, then connect with Apple Remote Desktop. There would be a default user/password for a virgin Mac, using the last six or eight digits of the MAC address. At least that's how I remember it.
Does anyone remember the details? It's even possible this is pre-OS X...
It's been suggested this question is a duplicate of How to setup a Mac (Mini 2015) without a monitor (or mouse or keyboard)?. That question may verify that the method I remember either no longer works. The question is more of a historical one, if anyone remembers this from years past.
[Update]: I found my manual of Apple Remote Desktop 2.0, from 2004 (Mac OS X 10.2.8). It makes no reference to any of this. I still think what I remember was a thing, but may have been from Classic MacOS days. So I've added the classic-mac-os tag to clarify, and removed references to this being a current OS question.