What are "SVCD scan offsets" ?

[SupaCoopa]

Can somebody please explain what SVCD scan offsets are? I see this option in MPEG editors/encoders but have no clue about it. Any info/link very welcome.

Cheers

[Kedirekin]

I believe scan offsets are little bits of data put in the user data stream that tell the player where each next (and last) GOP is located. I also believe some SVCD players need the offsets to be able to do fast forward and rewind.