The home variables are:
Category
Available name
Complex
Z1...Z9, Z0
Graphic
G1...G9, G0
Library
Function
Parametric
Polar
Sequence
Solve
Statistics
User-named
List
L1...L9, L0
Matrix
M1...M9, M0
Modes
Ans
Date
HAngle
HDigits
HFormat
Ierr
Time
Notepad
Program
Editline
Real
A...Z, θ
R-6