On Land

Environment Information
At Rill Architects we run ArchiCAD on macOS. If you work at Rill, this is your stuff. If you don't, but you work in ArchiCAD, you may find something interesting. Anybody else, I don't know.

You can't place a detail marker in a detail window. Rats.

You can change the linked drawing of a placed marker by opening the settings and clicking 'Browse' underneath the detail name.

I've updated the other post with this info.