Packet 0x96
According to Fuzziqer's documentation, Packet 0x96 is some kind of client checksum. What it is a checksum of, I have no idea (but knowing about the checksums in PSOBB, its probably a CRC32 of something). Clients expect a reply to this packet that is of type 0x97.
Dreamcast Packet Format (Client->Server)
| Bytes | Meaning |
|---|---|
| 0x00 | Packet Type (0x96) |
| 0x01 | Flags (0x00) |
| 0x02-0x03 | Packet Size (0x0008) |
| 0x04-0x07 | Checksum |
Dreamcast Packet Format (Server->Client)
| Bytes | Meaning |
|---|---|
| 0x00 | Packet Type (0x97) |
| 0x01 | Flags (Checksum Response) |
| 0x02-0x03 | Packet Size (0x0004) |
Checksum Responses
| Flag | Meaning |
|---|---|
| 0 | Bad Checksum |
| 1 | Ok |
Sending the bad checksum response to the client will cause the client to overwrite portions of the character data. Specifically on PSOGC, according to chaos_ak, it clears such information as your inventory, bank, material usage, and C-Mode completion. Kayak (and Kabes) add that it clears techniques as well.