2011

Z Axis
Aligns the user coordinate system to a specified positive Z axis.
The UCS origin is moved to the first point specified and its positive Z axis
passes through the second point specified.
Object Aligns the Z axis in the direction tangent to the endpoint nearest to
where the object was selected. The positive Z axis points away from the object.
Apply
Applies the current UCS setting to a specified viewport or all active viewports
when other viewports have a different UCS saved in the viewport. (UCSVP
system variable).
Viewport Applies the current UCS to the specified viewport and ends the UCS
command.
All Applies the current UCS to all active viewports.
1078 | Chapter 21 U Commands