Random ICAO Aimpoint Runway Markings

[SB4200]

Simple question... where do they come up with this random 400m aimpoint for ICAO runway markings? Is it based on a certain aircraft?

As I understand it 74's will use ~ 1500' (450m) aimpoint and most other airliners 1000' (300m). A380 geometry I have no idea!

[Doors to Automatic]

It's also interesting that the aimpoint seems to have been changed universally outside of the USA since around 1998.

It used to be c300m in (1000ft); now it is a bit further at around 400m.

(See example of the new position :
Photos: - Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/-/-/0924761/M/) )

Does anyone know why it was changed?