Texas Instruments TI-83 PLUS - Manual (Page 721)

TI-83 Plus Tables and Reference Information 718
Variables
User Variables
The TI-83 Plus uses the variables listed below in various ways. Some
variables are restricted to specific data types.
The variables A through Z and q are defined as real or complex
numbers. You may store to them. The TI-83 Plus can update X, Y, R, q ,
and T during graphing, so you may want to avoid using these variables
to store nongraphing data.
The variables (list names) L
1
through L
6
are restricted to lists; you
cannot store another type of data to them.
The variables (matrix names) [A] through [J] are restricted to matrices;
you cannot store another type of data to them.
The variables Pic1 through Pic9 and Pic0 are restricted to pictures; you
cannot store another type of data to them.
The variables GDB1 through GDB9 and GDB0 are restricted to graph
databases; you cannot store another type of data to them.
The variables Str1 through Str9 and Str0 are restricted to strings; you
cannot store another type of data to them.