Solution 14488: Rules for Variable Names on the TI-89 Titanium and Voyage™ 200.
What rules should I follow when naming variables on the TI-89 Titanium or Voyage 200?
The following rules apply when naming variables on the TI-89 Titanium or Voyage 200:
• A variable name can use 1 to 8 characters consisting of letters and digits. This includes Greek letters (but not p), accented letters, and international letters. Do not include spaces. The first character cannot be a digit.
• Variable names can use uppercase and lowercase letters. For example the names AB22, Ab22, aB22, and ab22 all refer to the same variable.
• Variable names cannot be the same as pre-assigned names by the TI-89 Titanium or Voyage 200. Pre-assigned names include built-in functions (such as abs), instructions (such as LineVert), and system variables (such as xmin and xmax).
Please see the TI-89 family and Voyage 200 guidebooks for additional information.