Well yes, there are double (or triple or more) identical setnames...For example pacman might be available in a lot of sofware lists...so why not call the set pacman over and over again. That's one of the reasons why you need separated rompaths for each software list
Ah, so I would want to set each software libraries to their own (ten/10 in total) even if they are related (e.g., a2600, c64, and pce & tg16):
I:\MAME\MAME Software List ROMs>dir
Volume in drive I is i
Volume Serial Number is ...
Directory of I:\MAME\MAME Software List ROMs
06/04/2016 09:03 PM <DIR> .
06/04/2016 09:03 PM <DIR> ..
06/04/2016 09:03 PM <DIR> a2600
06/04/2016 08:28 PM <DIR> a2600_cass
06/04/2016 08:28 PM <DIR> apple2
06/04/2016 07:01 PM <DIR> c64_cart
06/04/2016 07:01 PM <DIR> c64_cass
06/04/2016 07:01 PM <DIR> c64_flop
06/04/2016 07:01 PM <DIR> pce
06/04/2016 07:01 PM <DIR> pce_tourvision
06/04/2016 07:01 PM <DIR> tg16
06/04/2016 07:01 PM <DIR> ti99_cart
0 File(s) 0 bytes
12 Dir(s) 102,395,215,872 bytes free
Am I correct?