Contributor: WIM SMIT

(*

> What are the valid characters for a filename in DOS?

Its in the DOS manual!(DOS 5: page 72)
Valid:
   A..Z 0..9 _ ^ $ ~ ! # % & - {} () @ ' `

Unvalid:
    spaces/periods,
    names equal to: CLOCK$ CON AUX COM1,,COM4 NUL PRN
*)