To Delete a UCS Definition
Click
View tab
Coordinates panel
Named UCS
.
Find
In the UCS dialog box, Named UCSs tab, select the UCS definition you want to delete.
Press Delete.
You cannot delete the current UCS or a UCS with the default name UNNAMED.
Related Concepts
About Using Named UCS Definitions and Preset Orientations
Related Reference
Commands for the User Coordinate System (UCS)