Thanks for your question. There was a debate a few months ago amongst other mappers over whether the network tag for the London Overground lines should be London Overground or National Rail. A similar debate took place for the Elizabeth line. The outcome of the London Overground debate resulted in the route master and route relations network tags being set to London Overground (by other mappers), although it is interesting to note that the debate over the Elizabeth line went the other way. The rationale for my changeset is to simply set the network tag in the London Overground network relation to match the network tag in the child route master and route relations, for consistency. So, should the same rationale apply to the network tag in the network relation of the other rail lines in the UK? Yes, I think it should, but presumably they are already set to National Rail, as their child route master and route relations are presumably also set to National Rail.