In AutoCAD LT, you can use only one UCS in each drawing file. When you open an AutoCAD drawing file in AutoCAD LT, AutoCAD LT uses only the UCS from the current viewport. If you edit the drawing in AutoCAD LT, and then save it and reopen it in AutoCAD, you might notice some changes in the UCSs.

What is a lisp routine?

A lisp routine is a short program you write to do perform a specific action in ACAD. All the commands are LISP routines.

What is Lisp in AutoCAD?

Lisp is like a plugin. which runs different commands which are not available in AutoCAD. ” AutoLISP is a dialect of Lisp programming language built specifically for use with the full version of AutoCAD” Wikipedia. Personally I do not use AutoCAD since is a software used mostly for Architecture or Industrial Design.