Q: In setting up a program in Applications Manager, what do the upside down question mark and the inverted exclamation point do when used in the Comments field?

A: An inverted question mark (press (Fn)- (3)) inhibits the Press any key to exit from DOS ... message after finishing the application. An inverted exclamation point (press (Fn)-(FILER)) disables the System Manager and prevents switching to another application while the current application is running, giving the application total control of the console and serial port. This is needed to make certain DOS programs (intersvr, terminal emulators, etc.) work properly.

Neither special character is documented in early versions of the 100LX manual, though both appear in the 200LX manual and in later editions of the 100LX manual (they work the same on both machines).