True position without datums

[[SH...]]

My true position don't have datum, So i have to create a GBF alignment using that bore??

IMG_20220322_225251.jpg

[[ni...]]

in such case i will do :

localisation in B / A : (planar = B : rotation = C : X0 = B Z0 = A Y0 = A)

C is at 52 to datum B and 0 to datum A.

if you don't do that, what will you do with the "52" ?