u/Hyphen1582

I'm planning to buy a couple of tickets for an upcoming trip to Fukuoka, and I got this question about what the S, P, G, and SP categories or markings are on the ticket sites.

Where I'm from this is non existent, so I'm here to ask what do they mean or what is the difference between them.

Thanks!

https://preview.redd.it/vxy6zt7hkm0h1.png?width=942&format=png&auto=webp&s=a63c08080d26c7fb41074c39ccb6ae6075a5df5f