forum.datacad.com

Having system variables (technically these are called tokens) like LASTZ for the Calculator is great.

When modeling ZBase & ZHite values get changed frequently.

To save typing can additional variable names get added, abbreviating the longer variable names?

They are case insensitive:
ZBASE or Zb (just like the Coordinates / Hints toolbar shows!)
ZHITE or Zh
LASTX or Lx
LASTY or Ly
LASTZ or Lz

DataCAD is known for reducing keystrokes needed to do something.