It's ATE SuperBlue which I think is DOT4. It's not the synthetic stuff for show cars if that's what you're asking. It's a budget racing fluid - last I checked it had the highest boiling point per dollar ratio out there.
Actually I should have been more clear since the MK2 is a mystery to this group
. The ABS actuator has metal plates/covers attached to it on the underside, and the location of the unit means you can't remove the covers without removing the whole unit. I'm reluctant to do that for fear a new leak from the fittings will crop up or something (not to mention the mess it will make!). The under-covers are shaped in a way that they control the flow of leaking fluid like an irrigation system. The source is hiding.
I suppose for now I'll just let the leak be and hope it doesn't get worse.
Actually I should have been more clear since the MK2 is a mystery to this group

I suppose for now I'll just let the leak be and hope it doesn't get worse.