That's not really "sony naming format"... It's more "startup elf filename".
It (the PS2) works that way, because part of the copy protection of the disc relies on the exact name of the startup elf filename, which affects the display of the PS2 "PlayStation(r)2" logo when the game starts.
So SONY puts the startup elf name as that so the PS2 uses the game licence number "SLES-52095" (this is SONY's format) as part of the protection.
Because an indexing file is created when you install the game using the USB tool the OPL browser has no problem finding the proper details for the file you are trying to load.
Now, if you don't use an index file, the OPL program has to parse every single file you have on the USB storage and it would take a lot of minutes to read all the necessary data if you had a big game list. So having the startup elf filename on the first part of the file name is important to make it find the games, due to the way it works.
If it weren't like that, OPL would need to scan the whole USB device looking for games inside of ISO files and it would be painfully slow.
SCPH-10000_GH-001 SCPH-15000_GH-003 SCPH-18000_GH-008 SCPH-30001_GH-005 SCPH-30000_GH-016(V4) SCPH-30001_GH-010(V4)
2xSCPH-10190, 2xSCPH-10350, 2xSCPH-10280
"**** j0 hackers!"
-Sjeep (As seen on TOXIC OS ELF...)