A separate, but related, issue is on STARs into London. It happens you're put on a heading in the same direction as the arrival (so you're pretty much flying it laterally, but in HDG SEL). For traffic separation possibly? It seems the controllers anticipate you follow the arrival's altitude constraints. Is there something published in UK AIP or AIC about that too? Because as far as I am aware you're taken off the arrival and any altitude or speed constraints need to be reiterated. .