Holding points
Mariner9
The distance from the runway edge is the key here. Cat 1 holding points can be as little as 30m from the runway whereas the Cat2/3 hold will be further away as detailed earlier. ATC will clear you to the appropriate hold which in normal ops would be the Cat1. If low vis procedures are in force then it would be the Cat2/3 hold but at their discretion it could be the Cat 1 if there was no inbound traffic. This would be used to expidite departures if a queue was forming.