2011

UNNAMED is always the first entry if the current UCS is unnamed. World is
always listed and cannot be renamed or deleted. If you define other coordinate
systems for the active viewport during the current editing session, a Previous
entry is next. You can step back through these coordinate systems by selecting
Previous and Set Current repeatedly.
To add a UCS name to this list, use the Save option of the UCS command.
Set Current
Restores the selected coordinate system. You can also restore a selected
coordinate system by double-clicking its name in the list, or by right-clicking
the name and choosing Set Current.
Details
Displays the
UCS Details dialog box, which displays UCS coordinate data. You
can also view the details about a selected coordinate system by right-clicking
the name and choosing Details.
Rename (Shortcut Menu Only) Renames a customized UCS. You cannot
rename the World UCS.
Delete (Shortcut Menu Only) Deletes a customized UCS. You cannot delete
the World UCS.
Orthographic UCSs Tab (UCS Dialog Box)
Changes the UCS to one of the orthographic UCS settings.
Current UCS
Displays the name of the current UCS. If the UCS has not been saved and
named, it is listed as UNNAMED.
Orthographic UCS Names
UCS Dialog Box | 1987