FD; [ Pedant on ]
PAPI - Precision Approach Path Indicator as per RAE Bedford 'invention' (actually the idea was French).
Regulators or world wide interpretations may differ.
[ Pedant off ]
A long time ago - ILS electronic glide paths were created by reflecting the beam off the ground in front of the transmitting aerial. Thus GS origin was the distance proportional to x deg in front of the aerial position (not exactly correct because the beam was subject to parabolic distortion proportional to the aerial lateral offset).
Do modern ILS GS transmitters still use a reflected beam?
If so then the diagrams require amendment / relabelling.
If not, how is the beam origin and thus runway interception defined?