Wall+Wall
This command creates a new UCS at the intersection of the two extracted planes (both on walls).
No selection is required to launch the command.
Launch the command.
Click the first point on a wall using Define points. A local plane is extracted on this wall.
To delete this point, click Backspace or Delete.
In the same way, click the second point on another wall. A second plane is extracted on the wall.
The origin of the created UCS is the projection of the first clicked point on the intersection line.
The Z-axis of the created UCS corresponds to the WCS Z-axis.