Global variable

[DrD]

For published programs, or public consumption in general, I have to agree that using reserved variables can become an interference to pre-existing user data. This can be a preventable issue, as you've shown, if care is taken to back-up, then restore data at the end of the program. I have never published a program, per se. I have contributed suggestions designed to help others, which may have had that side effect, though. So in that sense, this IS a tangible reason to avoid using them.

On the other hand, I don't use reserved variables to store data that must be non-volatile. If lists or matrices are important enough to reside without compromise, I make a back up of the calculator, or use other variables to back up the reserved ones. The device itself is prone to 'issues' that, sometimes, make it necessary to Reset the device, clearing all memory. So the mere act of ever using reserved variables as some kind of permanent memory, is placing that data at risk.