Caching of domain Group Policy settings on Win XP Pro

I understand that once domain Group Policy settings have been applied
successfully, they are cached on the Win XP Pro client. Thus even if the
workstation is booted while not connected to the domain network (using a
cached User Profile), or if Group Policy is applied asynchronously, there
will be some sort of domain SDOU settings in effect from the get-go (even if
they aren't necessarily current). Now that I understand that much (or
believe so), I wonder if someone could explain where the SDOU settings are
cached. I'm aware of the NTUSER.POL files, but haven't been able to
establish if this is where the caching occurs, or if they're for some other
purpose.

I'd appreciate your assistance, as I'm trying to get all of this straight in
my mind for the 70-270 exam.

Thanks!