From the Wikipedia article on Dartmouth Basic at Dartmouth BASIC - Wikipedia
Variable names were limited to A to Z, A0 to A9, B0 to B9, ..., Z0 to Z9, giving a maximum of 286 possible distinct variables. Array names were restricted to A to Z only
I have found that Bitlash users tend to run out of eeprom before they run out of variable names. And at least they can give their functions proper names so they are steered toward that habit.
While I have the podium may I point out that the syntax of the Bitlash language is much less weird / more compatible with C and Javascript in the 2.0 version and if you haven't given it a look in a while it might be worth dusting off. Here's the User's Guide: http://bitlash.net/bitlash-users-guide.pdf
-br