This is example on a 20 Million Euro Xfer for Ferguson
https://www.transfermarkt.co.za/solidarityFeeCalculator/index
500 Euros for Hamilton - 400 for ABerdeen, 100 for Bologna + any Aberdeen Add ons
this is what i remember when i read into this previously - solidarity payment in perpetuity - there maybe be some quirk where not payable, between associations, ie within the UK